President elect Donald Trump (C), with his wife Melania Trump (L), and Senate Majority Leader Mitch McConnell (R), gives the thumbs up after a meeting in the Majority Leaders office in the US Capitol in Washington, DC, USA, 10 November 2016. EPA/SHAWN THEW

Republican leaders return to Washington on Monday to find a vastly different landscape than the one they anticipated — majorities in both chambers and a President-elect Donald J. Trump who they hope will help enact a sweeping set of policy priorities long stymied by divided government.

Lawmakers originally intended to use the “lame duck” session to pass a short list of bills, including an extension of sanctions on Iran, medical innovation legislation and a must-pass spending bill to avert a government shutdown on Dec. 9. Now Republican leaders, buoyed by Trump’s surprise victory, are expected to engage in a last-minute push making it easier for them to spend the next year repealing Obamacare, cutting taxes and rolling back many Obama-era regulations.

Trump’s victory heralds a golden age for Republicans on Capitol Hill

House Speaker Paul D. Ryan (R-Wis.) told reporters on Wednesday that he would be rethinking his approach to the year-end session in light of Trump’s election — but he declined to give any details about his plans.

“It is very exciting to be going into a lame duck where we have a Republican president following right after it,” Ryan said at a press conference in his hometown of Janesville, Wis. “I’m excited about that and we’re going to coordinate with our president-elect on just what they’re hoping we can achieve in the lame duck.”

Ryan’s own leadership of the House GOP now appears no longer at risk when Republicans meet this week on Capitol Hill to choose their leaders for the next Congress. Ironically, Trump’s election is likely to help Ryan maintain his grip on the speaker’s gavel, while a Trump loss would likely have caused disgruntled Republicans to threaten his hold on the job.

Rank-and-file GOP lawmakers would have been hard-pressed to defy Trump if he lost by supporting Ryan, who only tentatively backed the GOP presidential nominee. Instead, Republicans seem to be embracing Ryan and the status quo, even if significant policy disagreements linger just beneath the surface.

“Given all the other moving parts we have to deal with, given all the big challenges we have in front of us, there’s wisdom in taking the team we have in front of us, uniting that team, and moving forward as a nation,” Rep. Luke Messer (R-Ind.), chairman of the House GOP Policy Committee, said Friday in a C-SPAN interview.

One possibility being considered to make internal peace is to appoint a member of the hard-right House Freedom Caucus to a junior GOP leadership position. “I think it would strengthen our conference to have a broad cross section of [it] represented at the leadership table,” said Messer, who is running unopposed to keep his own slot.

House Democrats, on the other hand, are suddenly facing unrest in their own ranks after losing the presidency and under-performing in House races. Democrats once hoped to ride Trump’s unpopularity to a gain of 20 seats or more; instead, they netted only six additional seats, leaving Republicans with a commanding 47-seat margin.

House Democrats work to quell post-election anger with leaders

Before Trump’s election, most lawmakers were preparing to spend the lame duck negotiating a long-term bill to increase government spending and fund the government through next September. But conservatives are now expected to push for a short-term spending measure, perhaps as short as three months, that would keep government spending flat until Trump can be sworn-in as president.

Conservative lawmakers want to toss out the existing spending plan and pass a GOP-led budget that would slash domestic programs and could reduce the size of entitlement programs such as Social Security and Medicare.

It remains to be seen, however, whether their priorities will mesh with those of the incoming president, who Ryan has deep disagreements with on core tenets of GOP policy. Trump, for instance, vowed during the campaign to preserve Medicare and Social Security but Ryan believes in entitlement reform and has said since Trump’s election that Medicare needs to be revamped in order to repeal and replace Obamacare.

House Republicans deadlocked over spending will miss budget deadline, dealing a blow to Ryan

One key way Republicans could advance Trump’s plans during the lame duck is by reviving a stalled GOP budget framework for fiscal year 2017 in order to take advantage of a tool known as budget reconciliation. That process would allow next year’s Senate to pass GOP-backed measures, like repealing Obamacare, without the threat of a filibuster that requires 60 votes to surmount.

With spending bills stalled, focus turns to avoiding a shutdown fight this fall

Senate Majority Leader Mitch McConnell told reporters on Wednesday that repealing the healthcare law is tops on his list of priorities.

“It’s a pretty high item on our agenda,” McConnell said. “I would be shocked if we didn’t move forward to keep our commitment to the American people.”

That promise could prove impossible without Democratic help in what is likely to be a very slim Republican Senate majority next year — 52 to 48 seats if Republicans win as expected the Louisiana Senate runoff in December. It is unlikely that any Democrats will be willing to vote to repeal President Obama’s signature domestic legislation.

Congress Is Paul Ryan already eyeing Medicare cuts?

Besides extending government spending, congressional leaders will have to tie up a few scattered loose ends in the year-end session.

McConnell has indicated he wants the Senate to take up the 21st Century Cures Act, a bipartisan House-passed bill that streamlines the development of new medical treatments and prescription drugs while boosting funding for the National Institutes of Health and the Food and Drug Administration.

The House and Senate are in the midst of negotiating compromises on major policy bills — for energy programs and for water projects, which were not finalized before the election. The water bill includes federal aid for lead-tainted Flint, Mich., a top priority for Democrats. But Republicans could balk and seek to pass more GOP-friendly versions once Trump is inaugurated.

The House is also expected to tackle a ten-year extension of the expiring Iran Sanctions Act, or ISA, which forms the bedrock of existing U.S. sanctions against Tehran’s nuclear and missile activities. Though the White House maintains the law is unnecessary, lawmakers in both parties fear without it they will lose the power to “snap back” sanctions on Iran should it commit an egregious violation of the nuclear pact struck last year.

There are three proposals to extend the sanctions, including one that would strengthen punishment against Iran’s ballistic missile activities, cyber threats and espionage, and another tying a sanctions extension to increased military aid to Israel. But the House intends to vote on an unchanged version of the sanctions act, making it difficult for the Senate to switch gears in the short session. The only remaining hurdle is whether the White House will veto it – an option they have not yet ruled out.

The annual defense policy bill — which authorizes Pentagon programs and military operations — also remains in limbo. House and Senate negotiations are mired in disagreement over policy riders, including whether federal contractors can discriminate against LGBT workers and sage grouse encroachments on defense installations. That bill will also determine whether women will, for the first time ever, be compelled to register for a military draft. Obama vetoed an earlier version of the the defense policy measure and has already threatened a veto of the current one.

Fight over LGBT provision threatens to stall defense bill when Congress returns

Intraparty fighting is likely to continue to be a Capitol Hill trademark, though much if it might begin on the Democratic side.

There is widespread desire to see blanket changes to the party’s message, approach and leadership structure, according to many Democratic aides. A growing number of young and recently elected members want term limits for committee leaders and are pushing to elect at least one reform-minded member to the official leadership ranks. Progressive Rep. Keith Ellison (D-Minn.) is a leading contender to take the reins of the Democratic National Committee.

But there was, as of Friday, no member willing to openly challenge House Minority Leader Nancy Pelosi (D-Calif.) for the top leadership post. Pelosi has led House Democrats since 2003 and is renowned for her fundraising prowess and ability to manage the demands of an unruly caucus. But the party has been largely unable to reverse its electoral fortunes since losing 63 seats in 2010.

In the Senate, Republicans will begin the 115th Congress with their leadership largely intact. McConnell and his deputies have unquestioned support after preserving the GOP Senate majority in a tough year, though some committee chairmen will depart due to seniority rules.

House Democrats are expected to hold leadership elections Thursday, but a small group of rank-and-file members circulated a letter over the weekend to request that the process be delayed to allow Democrats more time to discuss what went wrong during the campaign and chart a path forward for the coming year.

There is somewhat more drama for Democrats, due to the retirement of Sen. Harry M. Reid (Nev.) after 12 years as the party’s top Senate leader. Sen. Charles E. Schumer of New York is in line to succeed Reid as minority leader, but a rung down the leadership ladder, Sen. Parry Murray of Washington has not ruled out a challenge to sitting Democratic whip, Richard J. Durbin of Illinois.

Sen. Debbie Stabenow (D-Mich.), a junior member of the current Democratic leadership, said much depends on Schumer’s wishes. “I believe he’s working with everyone and that we’ll have a unified leadership structure when he announces it,” she said Friday.