Colorado state legislators are considering historic legislation1 to restore workers’ collective bargaining rights by repealing provisions of an 82-year-old statute that limits Colorado workers’ freedom to form unions and collectively bargain.

At present, Colorado private-sector workers who form a union by winning a certification election administered by the National Labor Relations Board are prohibited from negotiating with employers over union security, unless they also pursue a state-administered second election, which they must win by the exceptionally high threshold of a 75% supermajority of those voting or 50% plus one of all eligible voters (not just those participating in the election)—whichever is greater. In other words, Colorado workers face uniquely steep barriers to securing full collective bargaining rights otherwise guaranteed under federal labor law.

While Colorado’s law is unique, its impact and its historical roots in periods of intense big business anti-union backlash and white supremacist campaigns to pass state legislation limiting multiracial worker power are not.

Data show that Colorado’s second election requirement has produced outcomes highly similar to those associated with so-called right-to-work (RTW) laws that prohibit negotiation over union security in other states. Colorado’s second election requirement has suppressed unionization rates, and declining unionization rates have been accompanied by a dramatic increase in income inequality in the state.

Colorado’s 1943 anti-union law led national backlash against worker organizing

Colorado’s state law currently limits workers’ freedom to bargain by banning negotiations over union security unless workers pursue and win (by supermajority) a state-mandated second election. The law in question, misleadingly named the “Labor Peace Act,” was enacted in 1943—just eight years after passage of the federal National Labor Relations Act (NLRA; LPA 1943; Mariam 2024).

The NLRA had declared “encouraging the practice and procedure of collective bargaining” to be “the policy of the United States” in order to reduce “obstructions to the free flow of commerce” and address the “inequality of bargaining power” between employees and employers (NLRA 1935). As union membership increased following passage of the NLRA, a business-backed counter-push in the early 1940s attempted to undermine the new federal labor law and entrench employer bargaining power. After losing court challenges to the NLRA (which was declared constitutional by the Supreme Court in 1937), business groups increasingly turned to state legislation in their attempts to constrain the growth of unions (Dixon 2007).

Colorado’s 1943 anti-union law enshrined in policy elements of a long history of state-sponsored suppression of union organizing. The 1914 Ludlow Massacre, for example, sparked national outrage when at least 20 people (including 11 children) were killed when Colorado National Guard troops set fire to a tent camp of immigrant miners’ families who had been evicted from company housing by the Rockefeller-owned Colorado Fuel & Iron Company while on strike (in turn sparking the bloody “Ten Days War” that followed; Andrews 2010).

In numerous other 19th- and early 20th-century mining strikes, state intervention played similarly decisive roles. Along with company security and private militias, state police and Colorado National Guard troops were often charged with protecting strikebreakers or forcing miners back to work, enabling coal operators to maintain production while refusing to recognize miners’ unions, much less bargain over demands for improvements in wages and mine safety (DeStefanis 2004).

Fueled by white supremacy, state anti-union laws spread in 1940s

In Colorado and elsewhere, 1940s state laws regulating union security were products of business backlash against increasing union activity generally, and in particular against multiracial organizing that had begun to challenge the hyper-exploitation of Black, brown, and immigrant workers in industries like agriculture or mining. Colorado’s 1943 law, along with anti-strike laws passed in in Arkansas, Mississippi, and Texas, laid groundwork for what soon became the spread of so-called RTW laws to other Southern and Western states over the next decade (Pierce 2017).

Historians have traced the origins of state RTW proposals to Southern conservatives like Texas antisemite Vance Muse. Muse’s white nationalist “Christian American Organization” focused on opposing unions associated with the Congress of Industrial Organizations (CIO) who had begun organizing Black and white sharecroppers, factory workers, and miners into expansive industrial unions. Muse promoted state RTW policies to Southern state lawmakers as key to maintaining the color line and arresting the advance of CIO organizing that threatened the racial hierarchies underpinning labor exploitation (Pierce 2017; 2018).

Colorado’s passage of anti-union legislation in 1943 was equally central to this history. White supremacist organizations had grown to significant influence in early 20th-century Colorado, with the Ku Klux Klan periodically amassing enough members to take over state government (and many local governments; Davis 2023; Phillips 2018). Influential mining companies like Rockefeller’s staunchly anti-union Colorado Fuel & Iron (CF&I) had for decades relied on state power to protect their interests in standoffs with the United Mine Workers of America (UMWA), whose leader, John L. Lewis, cofounded the CIO.

Starting in the 1930s, new federal policies had begun to challenge coal companies’ ability to crush unions in Colorado. For example, National Recovery Administration requirements linking federal contracts to union recognition compelled CF&I to begin bargaining with the UMWA in 1933 (Athearn 1985, 161). The start of WWII intensified federal intervention in labor relations in industries critical to national defense. By 1942, the National War Labor Board (NWLB) had invalidated a “company union” at CF&I’s Pueblo steel plant and brokered national coal settlements that included union security clauses in exchange for union no-strike commitments—drawing the ire of industrialists who had long refused to bargain over union security (Gorhan Rice Jr. 1942; Kratz 2018).

Colorado’s 1943 labor law incorporated the emerging RTW movement’s focus on regulating union security in the form of the second election, along with a long list of other measures constraining union effectiveness. For example, Colorado’s law prohibited union political activity (this was later declared unconstitutional); expanded the authority of state courts to issue injunctions blocking worker collective action; and prohibited secondary strikes, boycotts, and pickets, which some unions had successfully used to encourage hostile employers to recognize or negotiate with newly formed unions (Seligson 1959).

Colorado’s state law then served as a primary template for the 1947 Taft-Hartley Act, which significantly amended the NLRA and enshrined new restrictions on union activity into federal law. In fact, a Colorado-style second election requirement with a simple majority vote threshold was among new restrictions included in Taft-Hartley amendments, though Congress soon deemed the second election superfluous and removed it in 1951. Of more lasting import, Taft-Hartley affirmed the authority of states to enact RTW laws prohibiting union security agreements (Hogler 2009).

1977 Colorado legislation reinstating second election requirement part of resurgent anti-union RTW movement

For decades after passage of Taft-Hartley, much of the Colorado law—including the second election provision—was considered preempted because federal law covered similar areas. In 1976, a lawsuit supported by the National Right to Work Legal Defense Foundation prompted a court ruling that the second election requirement could be enforced. This in turn called into question the legality of thousands of Colorado collective bargaining agreements negotiated without a second election. In what labor law expert Raymond Hogler has characterized as a “deal forged in the heat of a political emergency” with “little policy debate about its merits,” lawmakers responded with a bill that retroactively validated existing collective bargaining agreements but imposed the second election requirement on all future unionizing workers in Colorado (Hogler 2007).

While the lawsuit and legislation leading to reinstatement of the second election requirement fell one step short of an outright ban on union security in the form of a RTW law (which the governor at the time had pledged to veto), it was fully entwined with resurgent late 1970s anti-union campaigns. These campaigns again focused on blocking NLRA reform, slowing the growth of multiracial unions—this time in public and service sectors, where women and Black workers had unionized in growing numbers through the ‘60s and ‘70s—and using state legislatures to regulate union security to frustrate union organizing and union stability (Phillips-Fein 2009, 185–212; Shelton 2017).

Weakened, outdated state and federal labor laws pose obstacles to unionization

Nationally and in Colorado, the share of workers covered by a union contract declined in the four decades since Colorado reinstated its second election requirement. Importantly, this decline was not because workers lost interest in having unions. In fact, during the same period, the number of workers saying they would vote to unionize if given the opportunity steadily increased (to around 60 million in our latest estimate), and public approval of labor unions is now at an historic high of 70% (McNicholas and Tahmincioglu 2022; Shierholz et al. 2024).

In a period of rising inequality (Gould and Kandra 2024; Bivens et al. 2024) and record corporate profits (Bivens 2023), it is no surprise workers want unions. When workers are able to collectively bargain, their wages, benefits, and working conditions improve (Bivens et al. 2017). On average, a worker covered by a union contract earns 10.2% more than a nonunionized peer in the same sector with similar education, occupation, and experience and has greater access to paid sick and vacation days, health insurance, and retirement benefits (Banerjee et al. 2021).

The growing gap between the millions of U.S. workers who say they want a union and the low percentage of workers who have been able to access union coverage is explained in part by broken, outdated federal and state labor laws. As noted above, federal labor law (the NLRA) has been weakened, both by court decisions and major 1947 amendments modeled in part on Colorado’s anti-union state law (Seligson 1959). Today, employers routinely exploit weaknesses in the law, mounting aggressive opposition to worker organizing and violating workers’ rights to organize with relative impunity.

Employers are charged with violating federal law in 41.5% of all union election campaigns, as shown in Figure A. And nearly a third of union election campaigns (29.3%) involve a charge that a worker was illegally disciplined, fired, or changed work terms for union activity. Beyond this, there are many legal tactics employers can use to thwart union organizing; employers spend roughly $400 million annually on “union avoidance” consultants to help them stave off union elections (McNichols et al. 2019; McNichols et al. 2023; Logan 2025).

This combination of illegal conduct and legal coercion ensures that in practice, a majority of union elections are characterized by employer intimidation and in no way reflect the free, fair choice to join a union guaranteed to workers under the NLRA. Additionally, many state laws—like Colorado’s—pose additional unnecessary obstacles to unionizing and limit workers’ collective bargaining rights.

Like so-called RTW laws in other states, Colorado’s anti-union law results in lower wages and benefits for all workers

Figure B shows states with right-to-work laws as of January 2025. Southern and Western states adopted the majority of RTW laws in the 1940s and 1950s. Since 2010, five additional states with historically above-average unionization rates—Indiana, Kentucky, Michigan, West Virginia, and Wisconsin—adopted right-to-work laws, newly limiting workers’ collective bargaining rights in those states. In 2023, Michigan became the first of these states to repeal its RTW law (thus is shown as a non-RTW state in the map; Sherer and Gould 2023).

RTW laws are designed to diminish workers’ collective power by prohibiting unions and employers from negotiating union security agreements into collective bargaining agreements, making it harder for workers to form, join, and sustain unions. As a result, states with RTW laws generally have lower unionization rates than non-RTW states (Cooper and Wolfe 2021).2 Figure C displays the unionization rate by state, measured as a 2021–2024 average to smooth data volatility especially pronounced in smaller states. It’s clear from the lighter shading in states with RTW policies, and in Colorado due to the LPA, that these laws continue to play centrally important roles in suppressing union membership levels in these states.

Figure D displays unionization rates in each year from 1983 to 2024, grouping states into three categories: RTW, non-RTW, and Colorado on its own because of its second election law. Notably, Colorado’s lower unionization rate closely resembles that of RTW states. The figure also illustrates the downward trend in union membership across the country over the last 40-plus years. The difference in unionization levels between RTW and non-RTW states remained striking throughout this period, and Colorado continues to track the experience of RTW states that limit workers’ collective bargaining rights.

Private-sector workers in RTW states are less likely to be covered by a union contract than peers in non-RTW states, even after controlling for other factors that can be related to unionization (such as industry, occupation, education, age, gender, race, ethnicity, and foreign-born status; Jones and Shierholz 2018). 

Consequently, all workers (whether unionized or not) in states with RTW laws tend to have lower wages. On average, workers in states with anti-union laws earn 3.2% less than their counterparts in states without such laws, translating to $1,670 less per year on average for a full-time worker (Sherer and Gould 2024). Workers in RTW states also experience reduced access to health and retirement benefits, and less safe workplaces–including a roughly 14% higher rate of occupational fatalities (Zoorob 2018).

Private-sector unionized workers are more likely to have these valuable workplace benefits. Figure E illustrates that unionized workers are 72% more likely to have employment-provided health insurance and 64% more likely to have employment-provided retirement benefits than their nonunion counterparts. About three-quarters of union workers have employer-provided health benefits compared to less than half of nonunion workers while over four-fifths of union workers have retirement benefits compared with half of nonunion workers.

By weakening unions, anti-union state laws fuel economic inequality

State policies like RTW laws that constrain workers’ rights to unionize and collectively bargain are fundamentally linked to key economic and labor market outcomes—including measures of inequality. Data show that unions reduce income inequality across the economy (Banerjee et al. 2021), counteract racial and gender labor market inequities (EPI 2021), and reduce public-sector pay gaps (Morrissey and Sherer 2022).

Through bringing workers’ collective power to the bargaining table, unions are able to win better wages and benefits for working people—reducing income inequality as a result. As shown in Figure F, there was less income inequality in decades in which union density was higher.3 But as unionization rates declined—particularly after 1979—income inequality grew.

Similarly, declining unionization rates in Colorado have been accompanied by a rising share of income accruing to the top 10% and Colorado’s income inequality has become even more extreme than national income inequality. Figure G shows that declines in Colorado’s unionization rate since 1978 were accompanied by a stark increase in income inequality, with the share of income going to the top 10% growing from just under one-third (31%) to now nearly half (48%) of all income in the state.

The erosion of collective bargaining over the last four decades has suppressed workers’ wages across the country. Median wages would be 7.9% higher if unionization hadn’t declined between 1979 and 2017 (Mishel 2021). This translates into over $3,900 annually in lost wages for a full-time worker.4

While Colorado’s anti-union state law is unique and bears a different label, it’s had a similar impact: At 7.7%, Colorado’s 2024 union membership rate was 22% below the national average of 9.9%. If we use the more expansive definition of unionization to include not only union members, but also those covered by a union contract, Colorado’s 2024 unionization rate was 28% below the national average (8.0% versus 11.1%).5

All workers are disadvantaged in states where laws have suppressed unionization, but disparities are especially pronounced for women and workers of color because of the role unions play in counteracting labor market discrimination and ensuring equal pay for equal work (Jones and Shierholz 2018; EPI 2021). For example, EPI research has shown that declining unionization rates are a major factor in the persistence and expansion of the Black–white wage gap in recent decades (Wilson and Rodgers III 2016).

Meanwhile, blocking workers’ access to unions especially benefits the rich and fuels income inequality. Four decades of declining unionization rates have ushered in sharp increases in the share of incomes going to the top 10%, staggering increases in CEO pay, and wage suppression for workers (EPI 2021). Nationally, the typical or median worker would have earned $1.56 more per hour (the equivalent of $3,250 per year) in 2017 had unionization rates held steady since 1979 (Mishel 2021).

Conclusion

It will take fundamental reform of our labor laws to rebalance and rebuild an economy capable of generating shared prosperity. At the state level, this reform must start with eliminating unnecessary hurdles to unionization, which Colorado lawmakers have the opportunity to do this year.

Following New Hampshire’s repeated rejection of RTW proposals (Skipworth 2025), Michigan’s 2023 repeal of RTW (Sherer and Gould 2023), and Missouri’s 2018 ballot initiative to reverse RTW laws, Colorado could become the latest state to protect or restore workers’ collective bargaining rights in recent years. Such state action is especially critical at a moment when the future of federal labor law is in question.

The second election requirement is a relic of an anti-union era of Colorado’s history defined by intense and often violent employer hostility to worker organizing in which state government was frequently an active partner. Today, at a moment when workers are looking to unions as critical vehicles for fixing what’s broken in our wildly unequal economy, it’s Colorado’s turn to play a leading role in helping to restore worker bargaining power after decades of its erosion.

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Acknowledgements

The authors are grateful to Emma Cohn and Joy Donnelly for excellent research assistance and to Penelope Kyritsis for expert editing.

Notes

1. Colorado General Assembly, SB25-005, “Worker Protection Collective Bargaining,” https://leg.colorado.gov/bills/sb25-005.

2. Unionization rates are measured as the share of workers in each state who are either a member of a union or represented by a union contract.

3. In Figure E, we use a slightly different definition of unionization because it is the only one available in the earlier years of data shown in the figure; to match Figure E, we use the same definition in Figure F. This is the union membership rate, slightly lower than the union coverage rate discussed in earlier charts because it does not include non-members who are nonetheless covered by a union contract.

4. Here, we are extrapolating from 2017 applying the 7.9% difference to the median hourly wage of $23.98 in 2023. For a full-time worker, this yields a difference of $3,940 per year. Further, this is likely a lower bound given the continued decline in unionization of 0.8 percentage points since 2017.

5. For more state-by-state comparisons on unionization, please visit EPI’s new State of Working America data library (EPI 2025).

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