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

As the world celebrates a new year, lawmakers gather at the United States Capitol to inaugurate a new Congress.

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

This marks a Republican trifecta as President-elect Donald Trump will also return to the White House later this 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 get started on an ambitious to-do list, but things may not be easy and their majorities in both chambers of Congress leave little room for disagreement. The first test of party unity will come Friday with the House leadership elections.

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

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

And it will be tested as soon as the session begins. The House cannot certify election results or pass laws until lawmakers select its next speaker — the House leader.

Despite Trump’s endorsement, current President Mike Johnson faces opposition from several members within 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, it could trigger a series of votes until Republicans unite around a lawmaker. In 2023, Kevin McCarthy needed 15 rounds of voting and four days to win the position of president.

Johnson already faces a tough “no” from Rep. Thomas Massie of Kentucky, but several other Republicans have moved into the “undecided” column.

The GOP was left with a five-seat majority when final House elections were called in the 2024 elections. But that number has shrunk after Trump appointed several House members to serve in his administration.

“Do the math,” Johnson said during a news conference in early December. “We don’t have anything to spare.”

In the Senate, lawmakers have already chosen their majority leader: South Dakota Sen. John Thune won an internal GOP vote.

This means senators can move on to official business on Friday, but will face challenges in other ways. Lawmakers are scheduled to begin a series of confirmation hearings on some of Trump’s controversial decisions. cabinet appointees.

The Senate must approve 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 defense secretary, Pete Hegsethwho faces 2017 sexual assault allegations that he denies, as well as his pick for secretary of health and human services, Robert Kennedy Jr.who is a vaccine skeptic with a history of spreading misinformation.

Trump’s picks were seen making their rounds at the Capitol last month to woo Republican senators. But nominees will have to appear before bipartisan committees, meaning the hearings could get heated as senators from both parties use their platform to address criticisms and complaints.

However, the Senate could choose to accelerate confirmation hearings for some national security candidates, following a New Year’s Eve terrorist attack in New Orleans that left 14 dead and a vehicle 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 is approved by a committee typically faces no opposition on the full Senate floor, but given some of the initial reactions to Trump’s picks, the road to confirmation could be bumpy.

One item at the top of Congress’ legislative to-do list is addressing Trump’s 2017 Tax Cuts and Jobs Act, which expires in 2025.

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

It marked the largest tax reform in decades. The biggest cuts were for businesses and the wealthy, and Democrats have called for them to be reversed.

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

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.

Maintaining provisions of the 2017 tax cuts would add roughly $4 trillion to the deficit over the next decade, according to the Congressional Budget Office. This may not sit well with many hardline Republicans who are adamantly opposed to increasing the nation’s debt.

The legislation is expected to advance several key Republican priorities, ranging from curbing illegal immigration to cutting government regulations.

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

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

Lawmakers will also have to address the debt ceiling: the total amount the United States can borrow to meet its obligations. The problem already arose at the end of 2024, when legislators faced a government shutdown.

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

Several priorities may be combined into what is known as a reconciliation bill, which allows Congress to pass a tax, spending and debt limit bill with just a majority. This method avoids the possibility of a filibuster in the Senate, in which opposing lawmakers could delay or even derail a vote.

Regardless of how they decide to approach it, lawmakers will likely spend more time at the Capitol addressing their priorities in the upcoming session.

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

The end of the last Congress allowed us to glimpse the influence that Trump and his allies have on the Congress agenda.

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

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

Both Trump and Musk have threatened to withhold funding and support from incumbent Republicans who supported the bipartisan spending bill, raising the question of how much influence they will have over the legislative agenda.

Musk and pharmaceutical entrepreneur Vivek Ramaswamy could have more opportunities to weigh in. The two 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 take back the House during the 2026 midterm elections. Expect to see left-of-center lawmakers vying for influence.

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