Chuck Schumer said on Sunday that he had secured enough support in Washington to become Senate majority leader. He spoke after several Democrats elected on Tuesday restated campaign pledges not to vote for him. The leadership contest now threatens to overshadow the party's midterm victory.

Mr Schumer told reporters in New York that a clear majority of the incoming Democratic caucus had committed to him. He said the party's priority was to check President Donald Trump, not to fight over titles.

Democrats won control of both chambers of Congress in Tuesday's midterm elections. The result erased the Republican Senate majority that had shielded Mr Trump's nominees and legislation since January 2025.

Mr Schumer has led Senate Democrats since 2017. He faced fierce criticism from the party's base in March 2025, when he supported a Republican spending bill to avert a government shutdown.

That backlash shaped this year's primaries. A number of Democratic Senate candidates said during their campaigns that they would not support Mr Schumer as leader. Several of those candidates were elected on Tuesday.

Progressive organisations, including Indivisible, had urged voters to back challengers who refused to commit to him. Since Tuesday, at least two senators-elect have said publicly that their position has not changed. They have argued that the party needs a leader who reflects its new generation of voters.

The dispute matters because Senate Democrats choose their leader by secret ballot of the full caucus. The vote is expected when new senators arrive in Washington for orientation in December. A narrow Democratic majority leaves little room for internal division over committee chairs, the filibuster and the use of subpoena power against the Trump administration.

Republican leaders seized on the split. A spokesperson for the National Republican Senatorial Committee said Democrats were "fighting each other before they have even been sworn in."

No senator has formally declared a challenge to Mr Schumer. Allies of the New York senator said privately counted commitments put him comfortably above the simple majority required. The outcome will test whether the anti-establishment energy that powered Democratic primaries survives contact with the Senate's seniority-driven culture.

"We won this majority together, and I intend to lead it together," Mr Schumer said. "The American people did not vote for a Democratic Senate so we could spend November talking about ourselves."