Who could replace Mitch McConnell when he steps down from Republican leadership in November? The 'Three Johns' are waiting in the wings as Tom Cotton also stages bid for a top GOP slot

Minority Leader Mitch McConnell announced he will be stepping down from his role as the top Republican in the Senate in November sparking debate over who could replace the longest serving Senate leader in U.S. history. 

There are 'three Johns' in the wings who could take over the prominent role, but there are others who could also throw their name in the ring.

In a tearful speech on Wednesday, McConnell, 82, said it was time for the 'next generation of leadership' and he had full confidence in his conference to choose his replacement. 

Now all eyes are on his two current and one former lieutenant - Sens. John Thune, John Barrasso and John Cornyn - who are all are considered the most likely to take the top role in Senate GOP leadership. 

A source familiar told DailyMail.com that Sen. Tom Cotton, R-Ark., is also planning to stage a run for a Republican leadership slot.

Additionally, Sen. Shelley Moore Capito, who is one of two women in Republican Senate leadership, could be a potential dark horse candidate in the race while Sen. Joni Ernst, another member of the Republican leadership, ruled herself out on Wednesday.

Sen. McConnell speaking on the floor of the Senate where he announced heh will step down as Senate Republican leader in November 

JOHN NO. 1: Sen. John Thune of South Dakota is currently Senate Minority Leader Mitch McConnell's No. 2 in Senate leadership 

John No. 1 is Sen. John Thune of South Dakota who currently serves as McConnell's No. 2 in Senate leadership. 

At 63, he's the youngest of the top three contenders. 

Thune has served in the Senate since 2005 after his shocking election win against then Senate Democratic Leader Tom Daschle. 

He won narrowly against the prominent Democrat 50.6 to 49.4 percent and put on display the state's increasingly rightward tilt.  

It was one of the most watched races in the 2004 cycle. 

Thune took the place as McConnell's No. 2 in 2019, as one of the other Johns - Sen. John Cornyn of Texas - was term limited out due to Republican leadership rules. 

Like McConnell, he had a falling out with former President Donald Trump over the ex-president's push to overturn the 2020 presidential election. 

But earlier this month, he endorsed Trump for president in the 2024 election. 

JOHN NO. 2:  Sen. John Cornyn of Texas previously served as McConnell's top lieutenant but Republicans term limit leadership positions, so Thune took over in 2019 

John No. 2 is Sen. John Cornyn of Texas, who previously served as McConnell's right hand in Senate leadership. 

Cornyn, 72, was elected to the Senate in 2002, and served as the GOP's Senate Whip from 2013 to 2019, after a successful run at chairing the National Republican Senatorial Committee. 

Before that he served as a district judge, on the Texas Supreme Court and as the Lone Star State's attorney general.  

Republicans term limit their leadership positions, so Cornyn's whip gig was taken over by Thune in 2019. 

Since then, he was the Republicans' negotiator in a bipartisan gun control bill that was passed after the mass shooting at an elementary school in Uvalde in Cornyn's home state of Texas. 

Like McConnell and Thune, Cornyn had been critical of Trump, saying at one point 'we need to come up with an alternative' GOP nominee in 2024. 

He endorsed Trump for president in January. 

JOHN NO. 3: Sen. John Barrasso is the current No. 3 in GOP Senate leadership and more likely to move up to the No. 2 spot if Senate Republicans get a new head honcho 

John No. 3 is Sen. John Barrasso of Wyoming and is currently the chair of the Senate Republican Conference, meaning he's the third most powerful Senate Republican. 

Barrasso, 71, is a orthopedic surgeon by trade, but also served as a rodeo physician for a time. 

He originally ran for the Senate in 1996 as the state's longtime Sen. Alan Simpson was retiring, but lost the GOP primary to state Sen. Mike Enzi, who won the general election in the deeply red state. 

He gained his seat after the death of Sen. Craig Thomas in 2007, after serving in the Wyoming state Senate. 

While Barrasso is more likely to take the No. 2 position, he does have a good relationship with Trump, who he also endorsed in the presidential race in January. 

A source familiar told DailyMail.com that Sen. Cotton will run for Senate leadership. Sen. Capito has also been floated as she serves in the current GOP Senate leadership

Two other potential contenders are Capito and Cotton.

Capito, 70, of West Virginia is the current vice chair of the Senate Republican Conference and would be the first woman to serve in the role. 

Cotton, 46, has served in the Senate since 2015. He currently serves on the Judiciary, Intelligence and Armed Services Committee.