The 118th session of the U.S. Congress opens Tuesday with all attention focused on whether Congressman Kevin McCarthy of California can secure enough votes from his fellow Republicans to become the speaker of the House of Representatives and second in line to the U.S. presidency.

The 57-year-old McCarthy, who for years has sought to lead the 435-member House, is now tantalizingly close to winning the speakership yet not quite assured of securing the 218-vote majority he needs.

Republicans won a narrow 222-213 majority in nationwide House congressional elections in November and will take control of the chamber from Democrats and outgoing House Speaker Nancy Pelosi. Democrats, who have been locked in a 50-50 split with Republicans in the Senate the past two years, gained a 51-49 edge in the elections nearly two months ago and will maintain a majority even though Arizona Senator Krysten Sinema later switched from Democrat to independent.

McCarthy, a staunch conservative, won 188 votes in a House Republican caucus in November, and since then has secured more support in his effort to reach the 218-vote majority for the speakership.

But a hard-right group of House Republicans — five or more — oppose McCarthy’s bid for the speakership, saying that he has not been devoted enough to the conservative cause.

The dissidents have vowed to vote against McCarthy, which would leave him short of the needed majority because all Democrats almost assuredly will vote for their newly selected party leader, Representative Hakeem Jeffries of New York.

Over the past several weeks, McCarthy has held numerous conversations with the band of Republicans opposing him to try to secure their support.

He has offered them a variety of changes to the way the House operates or appointment to committees where key legislation is considered. One change will give the small number of dissident Republicans the right to a House vote to declare the House speakership vacant if they disagree with the way McCarthy is handling party policy on legislation or expected investigations of U.S. President Joe Biden and his administration.

But so far, with less than a day before Congress convenes at noon Tuesday, McCarthy’s quest for the speakership hangs in the balance, even though no one has gained any substantial support as an alternative.

No vote for the House speakership has gone beyond a single ballot in a century, but it could Tuesday.

Choosing a House speaker occurs even before representatives are sworn into office for their two-year terms. Lawmakers will call out the name of their choice for House speaker from the floor of the chamber.

Should McCarthy come up short of the required 218 votes — or fewer if some lawmakers vote themselves as “present” in the chamber, lowering the number McCarthy would need for a majority — one or more new votes would occur. The clerk of the House would continue to laboriously call the roll of all 435 members until McCarthy, or someone else, reaches a majority to become speaker.