WASHINGTON (AP) — In the first seriously contested Senate Republican leadership election in decades, three senators are vying to replace longtime GOP leader Mitch McConnell when he steps down from the post at the beginning of next year and Republicans take back the Senate majority.

South Dakota Sen. John Thune, Texas Sen. John Cornyn and Florida Sen. Rick Scott have been furiously campaigning to win their colleagues’ support in the secret-ballot election Wednesday. All three are trying to convince their colleagues that they have the ear of President-elect Donald Trump and will be the best person to implement his agenda.

They are also trying to differentiate themselves from McConnell, saying they will give rank-and-file senators more power and be more communicative.

It’s not clear who will win, or if there will be multiple rounds of votes before a winner is chosen.

A look at the three candidates:

SEN. JOHN THUNE

Thune, 63, defeated then-Senate Majority Leader Tom Daschle in 2004 after arguing during the campaign that Daschle had lost his South Dakota roots during his years in Democratic leadership. Now Thune is running to become majority leader himself.

Well liked and a respected communicator, Thune has been perceived as a front-runner for much of the year. He is currently the No. 2 Republican in the Senate, and took over for McConnell for a few weeks last year when he was on a medical leave. He is also a former chairman of the Senate Commerce Committee.

As he geared up to run for leader, Thune spent much of the year campaigning for his colleagues. According to his aides, he raised more than $31 million to elect Senate Republicans this cycle, including a $4 million transfer from his own campaign accounts to the Senate’s main campaign arm.

One potential liability for Thune has been his previously rocky relationship with Trump. Thune was highly critical of the then-president as he tried to overturn his election defeat in 2020 and after the Jan. 6, 2021, attack on the Capitol by Trump’s supporters. Thune said then that Trump’s efforts to disrupt the peaceful transfer of power were “inexcusable.”

This year, though, Thune and Trump have talked frequently on the phone and Thune visited the then-GOP candidate at his home in Florida. Thune told The Associated Press over the summer that he views their potential relationship as a professional one. If they both win their elections, Thune said, “we’ve got a job to do.”

SEN. JOHN CORNYN

Like Thune, Cornyn is a popular and respected member of the Senate GOP conference. A former Texas attorney general and member of the state Supreme Court, much of his work has been on the Senate Judiciary Committee. He was also McConnell’s No. 2, the job Thune now holds, for six years before he was term-limited out of the job.

Cornyn, 72, has also spent much of the year courting his colleagues one by one and fundraising for them around the country. He has long been one of the best fundraisers in the Senate, and his aides say he has raised more than $400 million for party candidates during his 22 years in office.

In 2022, after a gunman stormed a Texas elementary school and killed 19 children and two teachers, Cornyn was tapped by McConnell to lead the GOP in negotiating gun legislation with Democrats. The bill, passed that summer, stepped up background checks for buyers under 21, increased prosecutions for unlicensed gun sellers and put millions of dollars into youth mental health services. While Cornyn has touted his work on the gun bill, it could cost him some votes with the conference’s most conservative members.

Cornyn also had some past tensions with Trump, including his early suggestions that Trump might not be the best GOP candidate to run in 2024. But he, too, has smoothed relations with the incoming president, meeting him when he was in Texas to campaign and visiting him in Florida.

SEN. RICK SCOTT

While Thune and Cornyn both have leadership experience and have spent the better part of the year methodically trying to woo individual senators, Scott is running a different kind of campaign. And he believes he has a distinct advantage: his relationship with Trump.

Scott, a former two-term governor of Florida and a successful businessman, was reelected to a second term in the Senate last week, beating Democrat Debbie Mucarsel-Powell by more than 10 points. He is a longtime booster of the incoming president, and has positioned himself as a strong ally. Scott traveled to New York to support Trump during Trump’s hush money trial earlier this year, and has openly said he wants Trump to endorse him.

He won a rush of support on social media over the weekend when he was endorsed by people close to Trump, including Elon Musk. But Trump has not weighed in on the Senate contest.

It’s unclear if Scott’s outside approach could win him more support in the clubby Senate. He won 10 votes when he challenged McConnell for the post in 2022, and he will be aiming to improve that count in the first round of balloting Wednesday.

Scott, 71, is part of a growing group of far-right senators who have criticized McConnell’s tenure and advocated for more power for individual members. Several senators in that group, including Utah Sen. Mike Lee and Wisconsin Sen. Ron Johnson, have endorsed him, arguing that his business experience and relationship with Trump should put him over the top.