Congress begins a new session today. Here are five things to watch

As the world rings in the new year, lawmakers are gathering at the US Capitol to usher in a new Congress.

Friday is the start of the 119th Congress, where the Republican leaders of the US House of Representatives and the Senate.

This marks the Republican trifecta as President-elect Donald Trump returns to the White House later this month. The US has not seen unified control of all three branches of government since 2017, when Trump was last in office.

Republicans are eager to get started on the to-do list, but things won’t be easy — and majorities in both chambers of Congress leave room for disagreement. The first test of the party’s unity will come on Friday with the House leadership elections.

Here are five things to watch out for as the new session of Congress begins:

Republicans may have a majority in the House, but not by much.

And it will be tested as soon as the session starts. The House cannot confirm election results or enact legislation until lawmakers choose their next speaker – the leader of the chamber.

Despite Trump’s endorsement, current speaker Mike Johnson is opposed by several members of his congress who do not believe he deserves another chance.

The party’s majority is so slim that if Johnson loses just two Republicans in his campaign, it could trigger several votes until Republicans join the legislature. In 2023, it took 15 votes and four days for Kevin McCarthy to win.

Johnson is already facing a tough “no” from Congressman Thomas Massie of Kentucky, but several other Republicans have put themselves on the “undecided” list.

The Republican Party held five seats when the last House race was called in the 2024 election. But that has dwindled after Trump took several members of the House to serve on his administration.

“Do the math,” Johnson said at a press conference in early December. “We have nothing left.”

In the Senate, lawmakers have already chosen their majority leader: South Dakota Senator John Thune won the Republican vote.

That means senators can get down to business on Friday, but they will face challenges in other ways. Lawmakers are expected to begin a series of negotiations to validate some of Trump’s challenges elected ministers.

The Senate must sign off on about 1,200 positions to guide the new president, but some have come up with talks that are drawing public attention. He will appear before the Senate committee for the first time and answer questions, before the full committee votes.

The nominees include Trump’s choice for secretary of defense, Pete Hegsethwho has been facing rape charges since 2017 that he denies, and his nomination for secretary of health and human services, Robert F. Kennedy Jrwho is a vaccine skeptic with a history of disinformation.

Trump’s options were seen circulating on Capitol Hill last month to win over Republican senators. But the nominees will have to appear before bipartisan committees — meaning debates could get heated as senators from both parties use their platforms to address objections and complaints.

However, the Senate may decide to expedite A definite reaction from some national security appointees – following the New Year’s Eve terrorist attack in New Orleans that left 14 dead and a car bomb outside Trump’s Las Vegas hotel.

“The US Senate must confirm President Trump’s security team soon. Lives depend on it,” Wyoming Senator John Barrasso wrote in a post on X.

Appointments that clear the committee are not usually challenged in the full Senate, but based on the initial pushback on Trump’s decisions, the confirmation process could be difficult.

One item rising to the top of the legislative agenda in Congress is addressing the Trump Tax Cuts and Jobs Act of 2017, which expires in 2025.

The 2017 law – which was passed while Republicans controlled the House and Senate – included a $1.5tn (£1.2tn) tax reform, changing tax brackets and lowering taxes for many taxpayers.

This marked the largest tax reform in decades. The biggest cuts went to businesses and the wealthy, which Democrats have called for reform.

Trump campaigned on the economy – promising to extend tax cuts, lower corporate taxes, and eliminate taxes on tips, overtime and Social Security benefits.

How Congress does it — expansion of the 2017 bill, combining old and new laws or alternatives — is up in the air.

Savings from the 2017 tax bill would add nearly $4tn to the deficit over the next decade, according to the Congressional Budget Office. This will not sit well with many Republicans who strongly oppose increasing the national debt.

Expect to see legislation move on a number of Republican priorities, from curbing illegal immigration to reducing federal regulation.

There may be proposals to cut military aid to Ukraine, introduce new tariffs, cut costs for clean energy and improve border security.

At a press conference in November, Johnson described the Republican plan that aims to reduce inflation, protect the border, restore national energy, establish “educational freedom” and “drain the swamp”.

Lawmakers must also address the debt ceiling — the total amount the U.S. can borrow to meet its needs. The story began as early as the end of 2024 when lawmakers met with a government shutdown.

Trump wanted lawmakers to raise or freeze the debt for every economy, but that provision was removed from the final version of the bill that passed both chambers.

It is possible that several important items will be included in the so-called reconciliation bill, which allows Congress to pass the tax bill, spending and debt limit by a majority. This approach avoids the possibility of a filibuster in the Senate, in which opposing lawmakers can delay or disrupt a vote.

However they choose to approach it, lawmakers may be spending more time on Capitol Hill to achieve their goals in the next session.

Senate Majority Leader John Thune has scheduled more days and weeks for the Senate – including work days on Mondays and Fridays, which are often considered travel days.

The end of the last Congress gave a glimpse at according to Trump and his allies participate in the Congress party.

Tech billionaire Elon Musk, who has been tasked with advising the Trump administration on cutting government spending, has posted several times on his X page to criticize Johnson’s spending spree and Democrats to prevent a government shutdown.

Trump and Vice President JD Vance joined in, and the bill was defeated.

Both Trump and Musk have threatened to withhold funding and endorsements from Republicans who have backed the dual investment plan, raising the question of how much influence they will have on the legislation.

Musk’s entrepreneur and pharmacist Vivek Ramaswamy may have more luck. The two will head a newly formed advisory committee focused on reducing regulations and spending.

On the other side of the aisle, Democrats are regrouping, hoping to take back the House in the 2026 midterm elections. Expect to see more center-left lawmakers vying for attention.

Groups within the party hope to shape their future — such as the Problem Solvers Caucus, a group of lawmakers focused on advancing bipartisan legislation; Blue Dog Coalition, a group of centrist Democrats; and the center-left, “pragmatic” New Democrat Coalition.