Johnson wins dramatic reelection as speaker after 2 GOP hard-liners switch votes

Trump is doubling down on his support for Johnson, and said a victory for Johnson would be a "big win for the Republican Party."

"Good luck today for Speaker Mike Johnson, a fine man of great ability, who is very close to having 100% support," Trump wrote in an early morning post on his social media platform.

"A win for Mike today will be a big win for the Republican Party, and yet another acknowledgment of our 129 year most consequential Presidential Election!! - A BIG AFFIRMATION, INDEED. MAGA!"

The House will meet at 11:00 a.m. for legislative business and then officially convene for the start of the 119th Congress at 12:00 p.m.

At noon, there will be a quorum call to determine how many members are present and voting. With the GOP’s razor-thin majority in the House, Johnson needs almost every Republican vote to win.

The election for speaker is expected to take place between 12:45 p.m. and 1:00 p.m.

Read more about what will happen on the first day of the new Congress here.

Johnson has publicly expressed confidence that he will retain the speaker's gavel, but spent the final day before the vote on Capitol Hill meeting with Republican holdouts.

Several House Freedom Caucus members were spotted at his office, many leaving the hourslong meeting dodging questions from reporters. The few who did speak said they thought they were making progress but none had committed to voting for Johnson.

Meanwhile, Trump's team and the president-elect himself were working behind the scenes this week to strike a deal with one GOP hardliner in particular -- Rep. Chip Roy of Texas -- sources told ABC News.