This legal battle could take years before there's a resolution.

In response to the Trump administration effort to revoke California's ability to set separate emissions rules from the Environmental Protection Agency, 24 states, plus attorneys general in Los Angeles and New York City, are now suing the National Highway Traffic Safety Administration in the U.S. District Court in Washington to block the effort.

"Two courts have already upheld California’s emissions standards, rejecting the argument the Trump Administration resurrects to justify its misguided Preemption Rule. Yet, the Administration insists on attacking the authority of California and other states to tackle air pollution and protect public health,” said California Attorney General Becerra said in a statement.

The Trump administration argues that using the EPA's less stringent emissions rules would be good for the economy by making vehicles cheaper. It also says that California shouldn't be able to set guidelines that are stricter than the federal government's guidelines.

California's stricter emissions rules aren't exclusive to the state, though. Several other states also adhere to these guidelines, accounting for over 40 percent of vehicle sales in America, according to Reuters.

“Today’s action meets President Trump’s commitment to establish uniform fuel economy standards for vehicles across the United States, ensuring that no State has the authority to opt out of the Nation’s rules, and no State has the right to impose its policies on the rest of the country,” Secretary of Transportation Elaine L. Chao said in a statement.

Experts predict the legal battle between the states and federal government could be a long one. It might even last beyond the end of President Trump's remaining term of office, Reuters reports.

In addition to attempting the revocation of California's ability to set its emissions rules, the Justice Department is also going after the state's stringent requirements by starting an anti-trust investigation against BMW, Ford, Honda, and Volkswagen. These automakers struck a separate deal with California so that they could establish and a miles-per-gallon requirement that was higher than the Trump administration's proposed level but lower than the Obama-era proposition.