Massachusetts Attorney General Maura Healey

Brian Snyder / Reuters

Within 24 hours of President Trump's executive order on immigration taking effect on Friday, legal challenges were filed in federal courts nationwide, and opponents promised more to come against that order and other parts of Trump's agenda.

But a separate, quieter legal fight against the White House's agenda was already underway. In the days after Trump's inauguration, Democratic state attorneys general, members of Congress, and civil rights groups went to court asking judges for permission to intervene in pending cases to defend positions they fear the new administration will step away from.

The cases at issue to date touch on the environment, sex discrimination, for-profit colleges, and consumer protection. The would-be intervenors argue that the Justice Department and agency lawyers may now no longer represent their interests, pointing to Trump's pledges to roll back federal regulations and undo the Obama administration's policies.

If their efforts are successful, it means that those cases wouldn't end if the Justice Department or other agency involved decides to withdraw, switch sides, or otherwise adjust their position.

Andrew Bradt, an expert on civil case procedure at UC Berkeley School of Law, said he couldn't recall a previous presidential transition period that so quickly saw so much action in court. As the Trump administration has swiftly moved on its policy agenda, opponents have had to act fast, he said.

“We’re not dealing in a world where various interest groups have had time to strategize a litigation approach. Rather, we have a bit of a free for all. And when there’s a free for all, that’s when intervention makes sense, because courts want to make sure that all of the relevant parties have a seat at the table,” Bradt said.

The intervention requests filed to date are largely preemptive. The Justice Department and other agency lawyers involved haven't made any announcements about whether they plan to change their litigation posture. But the lawyers seeking to intervene argue that Trump and his advisers have said and done enough to convince them that they needed to step in right away.

“There is a real concern about whether the new administration is going to continue to defend regulations and other laws that were passed during the Obama administration … Where there are legal challenges to these rules, they are entitled to a zealous defense,” said Brianne Gorod, chief counsel at the Constitutional Accountability Center. The center is representing two Democratic lawmakers seeking to intervene in a case challenging the constitutionality of the Consumer Financial Protection Board, which was created as part of the 2010 Dodd-Frank financial reform package.

There is precedent for other parties stepping in to defend litigation when the White House and Justice Department change course. In one especially high-profile example, House Republicans said they would defend the Defense of Marriage Act in court after the Obama administration announced it would no longer do so. The US Supreme Court struck down the law in June 2013.

To intervene, parties have to show that they have a concrete interest in the outcome of the case that the existing litigants wouldn't adequately represent.

Requests to intervene tied to the new administration have been filed in at least four federal court cases since Trump took office. In two of the cases, lawyers for the government had asked judges to push back deadlines to give them time to coordinate with the new administration. In the other two cases, the government hasn't filed anything acknowledging the change in administration.

CONSUMER PROTECTION: Three groups have separately asked to intervene in the Consumer Financial Protection Board case, which is being litigated in the US Court of Appeals for the DC Circuit. A three-judge panel ruled in October that the board's single-director structure was unconstitutional. On Nov. 18, the board — represented by its own in-house lawyers, not the Justice Department — asked a full sitting of the court to rehear the case. The Justice Department filed a brief in support. The court has yet to decide if it will grant that request.

On Jan. 23, state attorneys general from 16 states and the District of Columbia asked to intervene. They wrote that “there is reason to believe that the new administration will not maintain its defense of the CFPB.” It was possible, they said, that Trump would replace the director appointed by Obama, Richard Cordray, and replace him with “a person with a different policy agenda.” Days later, two Democratic members of Congress — Sen. Sherrod Brown and Rep. Maxine Waters — filed a request to intervene in the CFPB case, as did a group of public interest organizations and other entities with a connection to the board.

The Consumer Financial Protection Board and the Justice Department haven't responded to the intervention requests, but the companies that brought the original challenge oppose it. They filed papers on Jan. 27 arguing the court should deny the intervention request because it was filed after the deadline and the states failed to show that they had a direct interest in the outcome of the case.

ENVIRONMENT: In another case in the DC Circuit, involving a challenge to new greenhouse gas emissions standards for large trucks and other medium- and heavy-duty vehicles, a group of eight state attorneys general filed papers on Jan. 23 asking to intervene.

The motion didn't explicitly reference the Trump administration, but the states wrote that although their interests at the moment appeared to align with those of the Environmental Protection Agency and the National Highway Traffic Safety Administration, “that has not always been the case in the past and may not always be the case in the future.”

EDUCATION: On Jan. 24, five states and the District of Columbia asked to intervene in a case before the US District Court for the District of Columbia involving a major accreditor of for-profit schools, Accrediting Council for Independent Colleges and Schools. The company is challenging the US Department of Education's decision to no longer recognize it.

In a statement, Massachusetts Attorney General Maura Healey said that her office had intervened in the emissions case, the for-profit schools case, and the Consumer Financial Protection Board case to protect against “rollbacks by the Trump administration.”

CIVIL RIGHTS: In the Sixth Circuit, which sits in Cincinnati, the American Civil Liberties Union on Jan. 26 filed a request to intervene in a sex discrimination case that the Equal Employment Opportunity Commission brought against a funeral home. The ACLU, representing the transgender woman at the heart of the case, wrote in its motion that given the change in administration, their client “was reasonably concerned that the EEOC may no longer adequately represent her interests going forward.”

One pre-inauguration attempt to intervene in a pending case was rejected. In December, two individuals who said they benefitted from the Affordable Care Act asked to intervene in a challenge brought by congressional Republicans to how a piece of the health care law was funded. A federal district judge ruled in favor of Republicans in May 2016, but put her ruling on hold pending an appeal. The Justice Department took the case to the DC Circuit.

A three-judge panel denied the intervention request on Jan. 12 in a one-paragraph order, writing that the would-be intervenors had “not demonstrated that they are entitled to intervene in this case.” The court cited a 1994 case that laid out the standard for intervening, but didn't specify which factors weren't satisfied.

A lawyer familiar with the case told BuzzFeed News that it was possible the DC Circuit felt the request was premature, but that the challengers could make another attempt to join the case if “circumstances change.” Trump has pledged to repeal the Affordable Care Act, and signed an executive order on Jan. 20 ordering the executive branch to “minimize the unwarranted economic and regulatory burdens of the” law in the meantime.