Washington (CNN)Mississippi state Sen. Chris McDaniel is preparing to challenge Sen. Roger Wicker in this year's Republican primary, two GOP sources confirm to CNN.
Conservative firebrand Chris McDaniel to enter Mississippi Senate race, setting up divisive GOP primary
McDaniel is the conservative who nearly ousted Sen. Thad Cochran in a 2014 primary. He is holding a Facebook Live event Monday night that is intended to drive people to a rally in his hometown of Ellisville, Mississippi, on Wednesday.
"I have some important information to share about our political future," McDaniel says in the Facebook Live event invitation, adding that this week "should be interesting."
Politico's Alex Isenstadt first reported Monday that McDaniel will challenge Wicker.
McDaniel's entrance makes Mississippi the third state with a major Republican showdown pitting an incumbent or establishment favorite against a conservative firebrand. In Nevada, Sen. Dean Heller is being challenged by Danny Tarkanian. And in Arizona, Rep. Martha McSally -- the GOP establishment's preference to replace the retiring Sen. Jeff Flake -- faces two well-known outsiders, in former state Sen. Kelli Ward and former Maricopa County sheriff Joe Arpaio.
Some Mississippi Republicans expected that with the downfall of Steve Bannon, who'd encouraged McDaniel to challenge Wicker, and the expectation that Sen. Thad Cochran could soon step down, he would wait to run for Cochran's seat. But McDaniel was running out of time to decide: Thursday is Mississippi's filing deadline.
A Wicker campaign spokesman said Wicker's camp will wait until McDaniel announces his entrance into the race to comment.
Wicker supported Trump in 2016, and has been a reliable vote for Trump's agenda in the Senate. If McDaniel is successful, the race could shape up more as a referendum on Senate Majority Leader Mitch McConnell -- the sort of contest Bannon expected last year as he recruited what he'd hoped would become an insurgent slate of candidates.
Wicker was the chairman of the National Republican Senatorial Committee in the 2016 cycle, which means he enters the race with a vast fundraising rolodex.