Congress returns to a changed Washington as President-elect Donald Trump's hard-right agenda is quickly taking shape, buoyed by eager Republican allies eyeing a full sweep of power on Capitol Hill while Democrats are sorting out what went wrong.

Even as final election results are still being tallied, the House and Senate leadership is pushing ahead toward a second-term Trump White House and what he's called a “mandate” for governing, with mass deportations, industry deregulation and wholesale gutting of the federal government.

Trump is already testing the norms of governance during this presidential transition period — telling the Senate to forgo its advise-and-consent role and simply accept his Cabinet nominees — and he is staffing his administration and finding lawmakers willing to bend those civic traditions.

“Trump's going to deliver his deportations, the drilling, the wall — it's going to take all of us getting together,” said Rep. Ralph Norman, R-S.C., a conservative member of the House Freedom Caucus.

But first, the House and Senate leaders will hold internal party elections this week for their own jobs. Most of the top Republican leaders depend on Trump for their political livelihoods and have worked to draw closer to the president-elect to shore up loyalty.

House Speaker Mike Johnson, who is on the cusp of keeping a slim majority hold of the chamber with several House races still too early to call, will assemble his leadership team early Tuesday on the Capitol steps for a victory lap and agenda-setting.

In the Senate, where Republicans seized power from Democrats on election night, three Republican senators who are vying to become the new GOP leader have rushed to agree with Trump's plan for quick confirmation of presidential nominees.

“As Congress returns to Washington, we must prepare the Senate to advance that agenda legislatively and ensure that the president-elect can hit the ground running with his appointees confirmed as soon as possible,” GOP Sen. John Thune of South Dakota, who is seeking the leadership job, wrote in a Fox News opinion piece.

All told, it's a fundamental reshaping of not only the power centers in Washington, but the rules of governing, as Trump returns to the White House in January with a potential GOP-led Congress that is far less skeptical or wary of his approach than eight years ago, and much more willing to back him.

“This is going to be a very challenging time,” said Rep. Pramila Jayapal, D-Wash., the chair of the Congressional Progressive Caucus.

She described the “horrific immigration policies” that Trump promised voters and she insisted the progressives in Congress will provide an “effective check” on the new White House, much the way Democrats did during his first term by fighting efforts to repeal the Affordable Care Act and other policies.

At the same time, Jayapal warned Trump will have “many fewer restrictions."

"Our members are ready to take up the fight again," she said, standing alongside a handful of newly elected progressive lawmakers she called the “bright lights” joining Congress.

First tests will come during the “lame duck” period of the remaining days of this Congress, the eight-week sprint until Jan. 3, 2025, when the new lawmakers are sworn into office.

As lawmakers return this week they will be joined by dozens of new names in the House and Senate who are in town for freshmen orientation weeks and the private leadership elections scheduled for Wednesday.

But Republican senators are protesting that one of their own, newly elected Dave McCormick of Pennsylvania, is being excluded from orientation week by Senate Democratic Majority Leader Chuck Schumer because there are still uncounted ballots in his race. Schumer's office has said it is custom to wait until all the ballots are counted.

The Senate leadership race to replace outgoing GOP Leader Mitch McConnell is turning into a test of Trump loyalties, with the president-elect's allies — including billionaire Elon Musk and Make America Great Again influencers — pushing the senators to elect Sen. Rick Scott of Florida.

But Scott has not been the most popular candidate for the leadership post, and senators had been rallying around the two “Johns” — Thune, the second-ranking GOP leader, and Sen. John Cornyn of Texas. The outcome of Wednesday's private balloting behind closed doors is highly uncertain.

In the House, some conservative Republicans are quietly suggesting their own leadership elections should be postponed until the final results of the House races are resolved. Democrats will hold their House and Senate leadership elections later.

Johnson wants to retain the speaker's gavel and told colleagues in a letter last week he is ready to “take the field” with them to deliver on Trump's agenda. But he is expected to face detractors behind closed doors.

While Johnson only needs a simple majority during Wednesday's private voting to become the GOP nominee to be speaker, he will need a 218-member majority in January during a floor vote of the whole House.

A low vote total this week will show the leverage Freedom Caucus members and others have to pry concessions from Johnson, much as they forced then-Speaker Kevin McCarthy into a prolonged vote for the gavel in 2023.

And while Johnson predicts next year will launch the “most consequential” presidency and Congress in modern times, he has had difficulty this year leading Republicans who refused to go along with plans, forcing the speaker to often partner with Democratic Leader Hakeem Jeffries.

Johnson's troubles stem in part from his slim majority, but that could persist if Trump continues to tap House Republicans to fill his administration. Trump has already asked Rep. Elise Stefanik, R-N.Y., to be ambassador to the United Nations and Rep. Mike Waltz, R-Fla., to be his national security adviser.

“We're pretty much maxed out,” said Rep. Ronny Jackson, R-Texas. “Everybody understands that.”

In the weeks ahead, Congress faces another deadline, Dec. 20, to fund the federal government or risk a shutdown, and conservatives are redoubling their pressure on Johnson not to cave on their demands to slash spending.

The House and Senate also will consider replenishing the Disaster Relief Fund to help provide aid in the aftermath of Hurricanes Helene and Milton.

And with President Joe Biden preparing to exit and Democrats relinquishing their hold on the Senate, there will be pressure to confirm more judicial nominees and to usher out the door any other bills that could possibly become law before Trump takes over.