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

As the world rings in a new year, lawmakers gathered in the US Capitol to begin a new Congress.

Friday marks the start of the 119th Congress, with Republican majorities in both the US House of Representatives and the Senate.

This marks a Republican trifecta given that President-elect Donald Trump will also return to the White House at the end of the month. The United States has not seen unified control of all three branches of government since 2017, when Trump was last in office.

Republicans are eager to begin an ambitious to-do list, but things may not be easy — and their majorities in both houses of Congress leave little room for disagreement. The first test of the party’s unity comes on Friday with the election of leaders in the House.

Here are five things worth watching as the new session of Congress begins:

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

And it will be put to the test as soon as the session starts. The House cannot certify election results or approve laws until lawmakers select their next speaker – the head of the chamber.

Despite Trump’s endorsement, current speaker Mike Johnson faces opposition from many members of his caucus who are not convinced he deserves a second chance.

The party’s majority is so small that if Johnson loses just two Republicans in his campaign, he could start a series of votes until Republicans unite around a lawmaker. In 2023, it took 15 rounds of votes and four days for Kevin McCarthy to win the speakership.

Johnson already faced a hard “no” from Congressman Thomas Massie of Kentucky, but several other Republicans put themselves in the “undecided” column.

The Republican Party was left with a five-seat majority when the last races for the House were called in the 2024 elections. But this decreased after Trump tapped several members of the House to serve in his administration

“You do the math,” Johnson said during an early December press conference. “We have nothing to share.”

In the Senate, lawmakers have already chosen their majority leader: South Dakota senator John Thune won an internal vote of the Republican Party.

That means senators can move on to official business on Friday, but they will face challenges in other ways. Lawmakers are expected to begin a series of confirmation hearings for some of Trump’s controversies cabinet appointees.

The Senate must sign about 1,200 appointments for the new president’s administration, but some will come with tense hearings that attract public attention. They will first appear before a Senate committee and answer questions, before the full chamber votes.

The nominees include Trump’s pick for secretary of defense, Pete Hegsethwho faces sexual assault allegations from 2017 that he denies, as well as his pick for secretary of health and human services, Robert F. Kennedy Jrwho is a vaccine skeptic with a history of spreading misinformation.

Trump’s picks were seen making their rounds on Capitol Hill last month to win over Republican senators. But the nominees will have to appear before bipartisan committees — which means the hearings could speed up as senators from both parties use their platform to address criticism and complaints.

However, the Senate could choose to speed it up confirmation hearings from some national security candidates – following a New Year’s Eve terror attack in New Orleans that left 14 dead and a car explosion outside a Trump hotel in Las Vegas.

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

A nomination that clears a committee usually doesn’t face opposition on the full Senate floor, but given some of the initial backlash over Trump’s picks, the confirmation road may be bumpy.

One item coming to the top of the legislative to-do list for Congress is dealing with Trump’s Tax and Jobs Act of 2017, which expires in 2025.

The 2017 legislation – which was passed at a time when Republicans controlled the House and Senate – involved a $1.5bn (£1.2bn) overhaul of the tax code, changed tax rates and reduced tax rates for most taxpayers.

It marked the biggest tax overhaul in decades. The biggest cuts went to businesses and the wealthy, which Democrats have called for to reverse.

Trump campaigned on the economy — promising to extend tax cuts, also cut corporate taxes, and eliminate taxes on tips, overtime pay, and Social Security income Social.

How Congress does it — an extension of the 2017 bill, a combination of old and new legislation or by other means — is up in the air.

Keeping provisions from the 2017 tax cuts will add an estimated $4 billion to the deficit over the next decade, according to the Congressional Budget Office. This may not sit well with many hardline Republicans who are staunchly opposed to increasing the nation’s debt.

Expect to see legislation move on several key Republican priorities, ranging from curbing illegal immigration to cutting government regulations.

There may be proposals to reduce military aid to Ukraine, impose new tariffs, cut spending on clean energy and strengthen border security.

In a November press conference, Johnson outlined a Republican agenda that aims to reduce inflation, secure the borders, restore the country’s energy dominance, implement “freedom of education” and “drain the swamp.”

Lawmakers must also address the debt ceiling — the total amount the United States can borrow to meet its obligations. The problem has already appeared at the end of 2024 when the legislators faced a government shutdown.

Trump has demanded that lawmakers raise or even suspend the debt limit in any spending deal, but the provision was dropped from the final version of the bill that was passed in both chambers.

It is possible that several priorities can be combined in what is known as a reconciliation project, which allows Congress to pass a bill on taxes, spending and the debt limit with only a majority. This method avoids the possibility of a filibuster in the Senate, in which opposing lawmakers could delay or even derail a vote.

However they choose to approach it, lawmakers could spend more time face-to-face on Capitol Hill to address their priorities in the next session.

Incoming Senate Majority Leader John Thune has scheduled significantly more days and weeks for the Senate — including business days on Mondays and Fridays, which have traditionally been considered travel days.

The end of the last Congress offers a look at the influence that Trump and his allies have on the agenda of Congress.

Tech billionaire Elon Musk, who has been tasked with advising the Trump administration on government spending cuts, has posted dozens of times on his social media platform X to condemn a spending deal that Johnson he led with the Democrats to avoid a government shutdown.

Trump and Vice President-elect JD Vance joined forces, and the bill was canceled.

Both Trump and Musk threatened to withhold funding and approval from sitting Republicans who supported the bipartisan spending bill, raising questions about how much they will have on the legislative agenda.

Musk and pharmaceutical entrepreneur Vivek Ramaswamy may have more opportunities to weigh in. The pair will co-lead a newly formed advisory committee focused on cuts to regulations and spending.

On the other side of the aisle, Democrats are regrouping, hoping to win back the House during the midterm elections in 2026. Expect to see center-left lawmakers jockeying for influence.

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