Washington, DC – This week, it became official. Not only did the Republican Party win control of the United States Senate, but it also maintained leadership over the House of Representatives, after some of the last outstanding races were called.

That puts the party and its champion, President-elect Donald Trump, in a strong position.

Come January, Republicans will hold a “trifecta”, controlling the presidency plus both chambers of Congress.

And experts say the trifecta may pave the way for sweeping changes, with longterm repercussions.

“The level of opportunity that Donald Trump has right now is very high,” said Todd Belt, a professor at George Washington University’s Graduate School of Political Management.

In many ways, this year’s trifecta echoes the political landscape in 2016, when Trump won his first presidential bid: In that election, Republicans notched majorities in the House and Senate too.

But unlike the period after the 2016 election — when party discord scuttled some of Trump’s most ambitious agenda items — Republicans have firmly coalesced around Trump this time around.

Trump has also had years to gather support for his second term, having launched his re-election campaign as far back as 2022.

“Trump will be very, very strong,” Belt said. He pointed not only to the makeup of Congress but also the conservative supermajority on the Supreme Court and its recent ruling granting broad immunity to presidents.

A ‘relatively weak’ trifecta

Having a stronger grip on government has long been a Trump priority. Since his first term in office, from 2017 to 2021, Trump has repeatedly expressed his desire to make the executive branch more powerful.

“I have the right to do whatever I want as president,” Trump told a 2019 conservative summit for teens.

Trump has also chafed at the constraints of having to push his agenda through the legislative branch and deal with government bureaucracy. Even in his advertisements this year, he pledged to “throw off the sick political class”.

The US Constitution, however, sets limits on what the different branches of government can do.

As president, Trump will have the power to impose tariffs, alter how immigration is enforced and make sweeping changes to federal agencies and workers, even without congressional approval.

Other parts of Trump’s agenda — particularly related to government financing or reversing existing legislation — can only be achieved through Congress.

While a Republican trifecta may appear like a golden opportunity for Trump, the party’s slim margins of control in Congress may dim that lustre, according to Elaine Kamarck, the founding director of the Center for Effective Public Management at the Brookings Institution.

After all, the Republican majority in the Senate is only 53 seats, out of a total of 100.

On Wednesday, the party crossed the threshold of 218 seats to keep control of the House — but its majority is likely to be thin there too.

“The only time the trifecta stays shiny is when the margins are overwhelming,” Kamarck told Al Jazeera. “This is a trifecta, but a relatively weak one, and Trump’s going to have to be careful to make decisions and put forward [policy priorities] that they can make sure can get their majorities.”

The risk, Kamarck explained, is that extreme policy proposals could alienate certain Republicans, who may not fully support Trump’s “Make America Great Again” (MAGA) platform.

Even a few votes lost could prevent a bill from reaching the majority needed to pass.

“On basic policy, things like the tax cuts, like cracking down at the border, I’m sure he will actually be able to achieve a lot,” Kamarck said of Trump.

“But there will be other areas where he could get carried away with his MAGA stuff, and that could be a lot tougher.”

Party cohesion?

Already, Republicans have been urging cohesion among their party members. At a news conference on Wednesday, House Speaker Mike Johnson encouraged his colleagues to “stand with this leadership team to go forward”.

“The theme that you will hear over and over from all of our members, across the conference, is that we are unified and energised and ready to go,” Johnson said. “We have to deliver for the American people, beginning on day one.”

In a letter to party members immediately after the election, House Majority Leader Steve Scalise echoed that sentiment.

He wrote that he had been meeting with Trump’s team for months to “be ready to begin this work quickly and hit the ground running on day one in January”, according to the letter, which was obtained by PunchBowl News.

“Next Congress, we will be closely aligned with President Trump and Senate Republicans every step of the way to ensure success,” Scalise wrote.

Laura Blessing, a senior fellow at the Government Affairs Institute at Georgetown University, explained that Trump does indeed face less resistance from within his own party than he did in his first term.

She pointed out that seven Republican senators crossed party lines to convict Trump during his second impeachment trial, when he was accused of inciting an insurrection at the Capitol on January 6, 2021. Only three of them remain in the Senate today.

Meanwhile, in the House, just two of the 10 Republicans who voted to impeach Trump for insurrection remain.

But despite the hero’s welcome Trump has received since his re-election, Blessing warned against using “Republican” and “cohesion” in the same sentence.

Groups like the Trump-aligned Freedom Caucus have long ground legislation to a crawl in order to advance their policy desires. Emboldened by Trump’s second term, Republican firebrands are once again likely to butt heads with more moderate party members.

“I still think they’re going to make governance difficult because these are folks who cultivated a professional reputation as gadflies and crusaders,” she told Al Jazeera.

“How that manifests itself in this Congress, we’re going to have to wait and see.”

Overcoming the divide

Fault lines within the Republican Party will ultimately decide just how much Trump’s agenda will be codified into law.

But there will also be other obstacles preventing the Republican trifecta from achieving every policy goal.

In both houses of Congress, bills can be passed with a simple majority. But in the Senate, small groups — and even individual senators — can stall a bill indefinitely through endless debate, in a process known as the filibuster.

Only with a supermajority of 60 votes can senators choose to end the debate and pass the bill. Without Democratic cooperation, Republicans are likely to fall short of that number.

With budget bills, however, Republicans have another tool at their disposal to bypass the filibuster.

Both parties have increasingly relied on a process called “budget reconciliation” for speedy passage. That process allows budgets — and any legislation included with them — to pass with a simple majority, sidestepping the filibuster.

The Senate parliamentarian, a non-partisan office, ultimately determines what items can be dealt with through the “reconciliation” process.

‘Not just bend the knee’

In Scalise’s letter, he outlined several key policy priorities for the incoming Republican-led Congress.

They included locking in Trump’s proposed tax cuts, rolling back federal energy regulations and surging resources to the US-Mexico border, to prevent irregular migration.

While those agenda items have widespread Republican support, other items he proposed are likely to be more controversial.

Scalise called on Republicans to eliminate “woke ideologies” and boost federal protections for “election integrity”, a reference to Trump’s false claims of widespread election fraud.

Critics also question whether Republicans may roll back the 2022 Inflation Reduction Act, which includes sweeping measures to combat climate change, or the 2010 Affordable Care Act, which has made insurance more accessible for US residents.

A Republican trifecta will make these policy goals more attainable. But Kamarck of the Brookings Institute warns that the success of the Trump administration will likely come down to the president’s own actions — and how Congress reacts to them.

“He’s very strong. There’s no doubt about it,” Kamarck said. “But the only things that can undercut that strength are his own choices.”

She pointed to controversial nominations Trump recently made to cabinet-level posts.

He named Fox News host Pete Hegseth as his pick to be defence secretary, former Democrat Tulsi Gabbard to be director of national intelligence, and far-right Congressman Matt Gaetz to be attorney general.

Those nominations will require confirmation in the Senate by a simple majority. But Trump’s picks have already roiled some Republicans, including moderate Senator Lisa Murkowski, who derided Gaetz as an “unserious” candidate.

Belt, the professor at George Washington University, also saw the cabinet picks as potentially damaging the relationship between Trump and his fellow Republicans in Congress.

“It could really derail some of Trump’s momentum,” he said.

“And when you see a president lose momentum early in the term, then that emboldens other members of Congress to work against him and not just bend the knee to his will.”