In the wake of Donald Trump's Election Day triumph, Republicans hope to leverage their control of the White House and Congress to pass a sweeping new agenda for the U.S.

Key to making that happen is the Republicans' Senate leader, a role that's been held by Mitch McConnell for 18 years. The Kentucky senator, 82, announced his intention to step down in January, igniting a ferocious lobbying campaign to replace him.

Senate Republicans will choose a successor on Wednesday, via secret ballot. With the Senate returning to Republican control following three years with a Democratic majority, McConnell's successor will wield even more power than he has in recent times.

The Senate is also charged with confirming Trump’s Cabinet nominees, making them a vital stepping stone as he asserts control ahead of his second term as president.

For months, two longtime McConnell allies have been the main figures in the race: Sen. John Thune of South Dakota and Sen. John Cornyn of Texas. Both are considered pragmatists and deal-makers, raising plenty of money for the party.

Speaking to Fox News after the election, Thune gave his take on Trump's policy plans.

"That’s an agenda that deals with economic issues, taxes, regulations, energy dominance," Thune said. "That deals with border security and, as always, national security.”

Cornyn emphasized the national debt in an interview with Fox News.

"I know the challenges we have in terms of $35 trillion in debt, more money being paid on interest than on defense spending, and then obviously the broken border and so many other issues," he said.

However, Trump's Election Day success gave rise to a third possibility: Sen. Rick Scott of Florida. A staunch ally of the president-elect, he was the first lawmaker to join Trump in the New York courtroom during his hush money trial earlier this year.

"Whoever's going to be the Republican leader needs to work with President Trump," Scott said in an interview with ABC News’ Rachael Bade. "It's probably better to have a good relationship than not."

Scott is also a longtime friend of Susie Wiles, the Trump campaign manager who's been tapped for chief of staff.

It's also possible Scott's candidacy is designed to elicit concessions from McConnell’s successor and push the entire Senate further to the right.

The Senate's far-right members aren't interested in working with their Democratic counterparts on policy, instead focusing on government spending.

"I think we need to do everything we can to counter the policies and ideology of the left," Wisconsin Sen. Ron Johnson told ABC News.

Some also want a leader who will let the government shut down if elements of the Republican agenda aren't met -- a shift from McConnell, who avoided such shutdowns.

As the vote looms, Scott's allies are imploring Trump to endorse him in the hope it will propel him to victory.

Senate Republicans told ABC News that the president-elect won’t have much sway because the election is held by secret ballot, with Republican senators voting for their leader on Wednesday. The party gathered behind closed doors Tuesday evening to hear arguments

Despite this, he took to his social media platform Truth Social on Sunday to demand that the person who wanted the job agree to recess appointments. This would allow him to temporarily install appointments to federal vacancies without Senate approval.

Within hours of Trump's post, all three candidates essentially agreed.