There’s a quiet revolution underway in U.S. labor policy: In the face of crippling congressional gridlock, cities and states are increasingly lifting workplace standards on their own. In recent years, they’ve approved things like higher minimum wages, unprecedented paid leave policies and adopted laws that require bosses to give workers advance notice of scheduling changes.

But these churning municipal policy laboratories are also sparking some backlash. In response to the bevy of new progressive regulations, conservative state lawmakers are increasingly adopting so-called pre-emption laws barring local governments from tackling work-related policies on their own.

Today, the twin forces are colliding in the city of Birmingham, Alabama, which recently adopted a $10.10 hourly minimum wage. The move has ignited a fierce battle between the city’s largely black, liberal lawmakers and the state’s mostly white, conservative legislators. Under the gaze of observers nationwide, both sides are duking it out — and nearing the end of the fight.

Supporters say the hike is necessary because of people like Bush Paulding.

The 46-year-old puts in 40 hours a week at a McDonald’s in Birmingham, where he scrubs floors and sidewalks as a maintenance worker. He earns the federal minimum wage of $7.25 an hour, since Alabama has no pay floor of its own.

Paulding said he has worked “on and off” at restaurants in Alabama and Michigan, about 20 different gigs overall. In addition to McDonald’s, he said he used to work two other jobs — at Burger King and Applebee’s — to make ends meet and pay rent. Eventually, it became too much to juggle. Now, Paulding works only at McDonald’s, but as a result, can no longer afford a place of his own. He said he lives with friends now.

“Every day it’s a challenge,” he said. “Some days, it’s hard to get up. You just feel like you’re in a rat race.”

An estimated 40,000 of his fellow Birmingham residents are in a similar position and earn less than $10.10 an hour, according to a report from the left-leaning National Employment Law Project. That’s about a fifth of the city’s population, the group estimated.

The largest city in Alabama, Birmingham first voted to lift pay last August. According to the original bill, the first phase of the wage hike would have taken effect in July 2016, lifting the pay floor to $8.50. It would reached $10.10 an hour in July 2017.

But then state lawmakers stepped in: Earlier this month, Rep. David Faulkner, a Republican from the wealthy Birmingham suburb of Mountain Brook, introduced legislation that would prevent cities from enacting their own minimum wage rates. Faulkner did not respond to a request for comment.

The same day Faulkner introduced his bill, Birmingham city council members passed their own law that advanced the first phase-in of the city’s wage hike to March 1. The idea: Getting the pay raise in place before the state’s law takes effect would give the city’s minimum wage better legal standing.

The drama has only ramped up further: Faulkner’s bill passed the House last week and a Senate vote is expected as early as Thursday. Meanwhile, Birmingham lawmakers are still trying to stay one step ahead of their counterparts in Montgomery, the state capital. On Tuesday, the city council passed yet another bill, slating the entire $10.10 pay hike for Wednesday. It takes effect as soon as the mayor signs the bill.

It may still take some time for the legal smoke to clear: Even if the city manages to get its law on the books first, the state of Alabama likely has the advantage in court, according to legal experts. The state attorney general, a Republican, has criticized Birmingham’s recent moves and said businesses need a reasonable amount of time to comply with the law. Court battles are likely.

The Business Council of Alabama is one of the biggest supporters of Faulkner’s bill. CEO William Canary said legislators are only acting in the best interest of the state.

“Instead of raising small businesses labor costs and creating more barriers to entry-level employment, government should focus on policies that actually help reduce poverty and create jobs,” Canary said in a statement. “Alabama businesses are already subject to and are complying with numerous government regulations at the federal, state and local level. This bill will prevent even more onerous regulations from being imposed.”

Bush Paulding feels differently. “I think it’s unfair, it’s inhumane,” he said. “To them, you’re a piece of dirt ... They’ll talk about how this is going to affect the small business owners, but what about the 40,000 people [making under $10.10 an hour]?”

Yannet Lathrop, researcher and policy analyst at the National Employment Law Project, said supporters of pre-emption are violating their supposed small government principles.

“I would call it a little bit of hypocrisy on their part,” she said. “These conservative legislators say they support local control but not when it comes to low-wage workers.”

In Lathrop’s view, Faulkner and company’s motivations are clear: They’re not about having clear regulations; they’re about blocking minimum wages.

Alabama is one of a growing bunch of states to consider the pre-emption of local labor-related bills. Last year, Michigan approved a law that blocks municipalities from passing wage hikes or paid leave laws. Missouri legislators did the same — much to the chagrin of the cities of Kansas City and St. Louis, which had both approved minimum pay increases. (Kansas City eventually repealed its wage hike and St. Louis’ was struck down in court.)

This year, lawmakers in Washington, New Mexico and Idaho are all considering comparable legislation. Last fall, Iowa’s Johnson County began enacting a modest minimum wage increase, something Lathrop suspects may generate similar pushback from hostile state lawmakers.

The backlash comes amid a historic wave of local wage increases. Since 2012, 28 counties and cities have adopted minimum wage laws, according to the Center for Labor Research and Education at the University of California, Berkeley. Before 2012, just five localities had such regulations on the books.

Much of the momentum has come from the so-called Fight for 15, a low-wage workers protest movement backed heavily by the Service Employees International Union. Seattle, San Francisco and Los Angeles are all in the process of phasing in $15 minimum wages.  

Paulding, who said he met a Fight for 15 organizer at the McDonald’s where he works and has attended demonstrations in support of higher pay, said he won’t be discouraged if the state blocks Birmingham’s higher wage from taking effect. “No matter what happens, we’re not going anywhere,” he said.