As Donald Trump moves to fill his administration with polarizing figures like former Florida Rep. Matt Gaetz and former presidential rival Robert F. Kennedy Jr., he may need Congress to heed his demand to allow him to bypass the traditional confirmation process and appoint his picks without Senate approval.

The president-elect has insisted that rather than put his nominees through an extended public vetting process, the GOP-led Senate should take extended breaks that would allow him to make recess appointments.

Experts in American democracy say Trump’s call is the first major post-election test for Republicans in Congress of whether they will stand up for traditional checks and balances or bend to Trump’s desire not to have his choices questioned. The Constitution dictates that while the president gets to nominate key executive branch officials, it is up to the Senate to provide “advice and consent.”

If the Senate agreed to adjourn for the purpose of Trump filling his government without congressional input, it would be “an absolute abdication of their constitutional power,” said Sarah Binder, a political science professor at George Washington University.

“It’s saying, ‘Look, we are so loyal to President Trump, we’re so loyal that we’re going to choose him over our rights and our responsibilities as senators,’” she said. “It doesn’t get more stark than that.”

The question of whether Trump could circumvent Congress to install the people he wants has come into sharp focus this week as he has accelerated the pace of appointments.

Gaetz, an inflammatory Trump loyalist who has come under investigation by the House Ethics Committee, drew pushback even from some Republican senators when the president-elect picked him as his nominee for attorney general.

Kennedy was picked Thursday to lead the Department of Health and Human Services, spawning an immediate backlash from many in the medical community over his outspoken vaccine skepticism. Former congresswoman Tulsi Gabbard, who was selected for national intelligence director, has drawn scrutiny from national security experts who question her ties to Russia and Syria.

Although all could conceivably win support from a majority of senators during a traditional confirmation process, it is not assured in a body where Republicans hold 53 seats, a relatively narrow majority.

Sen. Cory Booker, D-New Jersey, said it would be “frustrating” if Republicans allowed Trump to subvert the Senate’s advice and consent role.

“I think people on both sides of the aisle would express that and from what I’m hearing from senators on both sides of the aisle, is that folks are not going to let that happen,” he said.

At least some Republicans, however, have expressed an openness to it.

Earlier this week, as Republican senators jostled over who would replace Mitch McConnell as their leader, Trump posted a warning on Truth Social: “Any Republican Senator seeking the coveted LEADERSHIP position in the United States Senate must agree to Recess Appointments.” He argued that otherwise it would take too long to get his nominees in place, and he wanted those top jobs filled “IMMEDIATELY.”

Republicans chose Sen. John Thune, R-South Dakota, to lead them. While in contention for the top job, Thune said he was open to recess appointments if needed to get Trump’s nominees in place quickly.

On Thursday, Thune expressed a preference for using “the regular process to get these nominees through” and said his “intention is to get these folks going and get voting.” But he also noted that there are procedures in place for using recess appointments.

In addition to the Cabinet, there are more than 1,000 executive branch positions that are subject to Senate approval. The Constitution allows for the president to fill vacancies if Congress is away, and presidents of both parties have used congressional recesses to make appointments. The framers provided that power at a time when travel to and from the nation’s capital could take weeks.

Since then, strict rules and procedures have developed for both recessing and making recess appointments, making the prospect of filling a Cabinet with recess picks challenging.

The Supreme Court weighed in on recess appointments in 2014 after Barack Obama used a short recess to fill three spots on the National Labor Relations Board amid inaction in the GOP-held Senate on the nominations.

The court decreed that the Senate needed to be on recess for at least 10 days before a president could make a recess appointment. For either chamber to adjourn for longer than three days requires approval from the other.

Democrats in the Senate could use procedural tactics to slow down a vote to adjourn that could require a 60-vote filibuster-proof majority to overcome. And the Republican majority in the House is projected to be narrow, meaning that calling a recess could be tricky.

But Trump may have another avenue to try to bypass the Senate, experts say, one that dramatically departs from historical norms. Rather than wait for Congress to adjourn, as presidents have done, he could try to instruct them to leave for the sole purpose of installing his nominees without their consent.

Edward Whelan, a prominent conservative scholar, wrote in an op-ed published in The Washington Post on Thursday that he has heard the Trump team is considering using an obscure constitutional provision that gives the president the power to adjourn Congress if the House and the Senate cannot agree on the timing of an adjournment. No president has ever used that authority.

Whelan wrote that late Supreme Court Justice Antonin Scalia, a strict constitutionalist, “would be aghast at the notion that a president could create an intrasession recess for the purpose of bypassing the Senate approval process for nominations.”

He urged House Speaker Mike Johnson, R-Louisiana, to block any such plan. The Trump transition team did not respond to a request for comment.

Among Senate Republicans, the idea of allowing Trump’s nominees to skirt the confirmation process has been met with mixed reactions.

“I’m hesitant to give up any aspect of our role when it comes to advice and consent. That’s what we do. President names and we provide consent,” said Sen. Lisa Murkowski, R-Alaska, who has signaled her opposition to Gaetz’s nomination.

Others, like Sen. Josh Hawley, R-Missouri, said Trump was within his constitutional authority to make recess appointments and said it should send a message to Republican leadership to move through confirmations quickly. He also said it should send a message to Democrats that if they attempt to obstruct Trump’s nominees, “then I think the answer is fine, that we’re going to recess and allow the president to exercise his constitutional authority.”

Sen. Kevin Cramer, R-North Dakota, said senators are “very protective of our authority and responsibilities,” but he could see moving to a recess if Democrats were holding up the process. He said he would not support Trump using a recess appointment if objections to a nominee were coming from Republicans.

Experts said they see the recess appointment question, while relatively arcane, as a fundamental test that could set the tone for the next four years.

“If the Senate does agree to do this, they will be signaling that they no longer see themselves as a truly coequal branch of government,” said Dan Farber, a professor at the University of California at Berkeley School of Law.

Ira Shapiro, a former Democratic Senate staffer and author of three books about the Senate, went further, calling it “an early test of whether there are guardrails to stop” Trump.

“If the Senate acquiesces, we will have taken a long step toward an authoritarian system,” Shapiro said, adding that he hoped Thune would “see this for what it is, an unacceptable usurpation of power.”

Marianne LeVine, Dylan Wells and Meryl Kornfield contributed to this report.