Republican senators are worried about state Sen. Chris McDaniel's, R-Ellsberg, Mississippi Senate campaign and are prepared to once again block him from ousting one of their own incumbents.

As Republicans hold onto a slim 51-49 majority in the Senate, they have prioritized getting Republican Party incumbents and their top recruits across the finish line, especially after losing a seat to Sen. Doug Jones, D-Ala., last year.

This means re-electing Sen. Roger Wicker, R-Miss., electing a replacement for Sen. Thad Cochran, R-Miss., and keeping out insurgent candidates they fear will jeopardize winnable races, as Roy Moore did in Alabama. McDaniel lost a GOP primary to Cochran in 2014.

"Obviously, we're all concerned," said Sen. John Cornyn, R-Texas, the second-ranking Senate Republican. "We want to make sure people who are going to be productive and want to actually get things done are elected, but that's the choice of the voters of Mississippi and not people like me."

Cornyn chaired the National Republican Senatorial Committee during the 2012 cycle, when Todd Akin and Richard Mourdock cost the party seats in Missouri and Indiana, respectively, by making controversial comments that overtook their campaigns. Some in the GOP circle see McDaniel as a candidate in the mold of Moore, Akin, and Mourdock, making life difficult for Senate Majority Leader Mitch McConnell, R-Ky.

"You always [worry], but not really with respect to Mississippi," said Sen. Thom Tillis, R-N.C., and co-chairman of the NRSC.

"The fact of the matter is we lost two races in this class, the last time we should have never lost," Tillis said, referring to Alabama. "We expect our members to be on their game."

In their push to deny him a nomination win, Republicans are going back to the same playbook they used to defeat Rep. Mo Brooks, R-Ala., in the Alabama Senate primary by bashing McDaniel for comments in 2016 that were critical of President Trump.

Like Brooks, McDaniel supported Sen. Ted Cruz, R-Texas, and panned Trump. On multiple occasions, McDaniel questioned Trump's conservative credentials, saying it was "very, very evident" he isn't a constitutional conservative and that it is "debatable" that he was a great businessman.

This gives Wicker backers tons of ammo against McDaniel, already deployed in an ad released Wednesday. They hope Trump's support combined with a desire to nominate winners will keep McDaniel out of Washington.

"Alabama is an object lesson in the type of tragedy that can strike for Republicans when they nominate a lunatic," said one GOP strategist. "He has all of the Trump bonafides of Mo Brooks, and, by the way, all of the moral flexibility of Roy Moore in the minds of many Mississippi primary voters who remember his campaign breaking into a nursing home."

While McDaniel is continuing his run against Wicker, all eyes are on Mississippi Gov. Phil Bryant to see who he will nominate in early April to replace Cochran in the upper chamber. Depending on who that is, it is possible McDaniel would shift to that race rather than challenge Wicker in the primary.

Despite framing himself as the true conservative in the race and a potential thorn in McConnell's side, McDaniel's campaign says the state senator is a middle-of-the-road conservative Republican in one of the reddest states in America. On the other end, Wicker, seeking his second full term, is too liberal.

"He's in the middle ... and Wicker is out in left field," said a source close to McDaniel's campaign. "If Mississippi can't send a conservative to the Senate, who can?"

McDaniel's campaign has also been quick to dispel all comparisons to Moore after last year's loss, given that McDaniel doesn't have the issues Moore had with reports of sexual improprieties that plagued him in his campaign. Not all Republicans think the comparison will stick.

"Well, I don't know if he's Roy Moore," said Sen. Richard Shelby, R-Ala. "Roy Moore's unique," he added with a laugh.