Mississippi State Sen. Chris McDaniel (R-Ellisville) and sons Chamberlain, 6, left, and Cambridge, 11, listen as their father speaks with a supporter. (Rogelio V. Solis/AP)

Insurgent Mississippi conservative Chris McDaniel plans to run for retiring Sen. Thad Cochran’s seat, ending his primary challenge against the state’s other Republican senator, Roger Wicker.

“By announcing early, we are asking Mississippi Republicans to unite around my candidacy and avoid another contentious contest among GOP members that would only improve the Democrats’ chances of winning the open seat,” McDaniel said in a statement Wednesday.

His decision spares Wicker a potentially bruising primary. But it opens up a new challenge for Republican officials who don’t like the controversial conservative state senator.

Even after McDaniel launched his campaign against Wicker, he left open the possibility of running for Cochran’s seat. The dynamics of an open race without a Republican primary appear more favorable to McDaniel than challenging a sitting senator who had the support of President Trump.

Cochran announced this month he will resign on April 1. Stepping down will trigger a special election to be held on the same day as the rest of the midterm elections: Nov. 6.

Gov. Phil Bryant (R) has the authority to appoint an interim successor. Both Trump and Senate Majority Leader Mitch McConnell (R-Ky.) urged Bryant to appoint himself, but the popular governor has said he will not do that.

It’s not clear whom Bryant will appoint. Names mentioned in GOP circles include state Agriculture and Commerce Commissioner Cindy Hyde-Smith, Lt. Gov. Tate Reeves and Secretary of State Delbert Hosemann.

Republicans are defending a 51-t0-49 Senate majority this year. Some in the GOP say they believe McDaniel imperils that majority. His hard-right positions could lead centrist Republicans to vote for a Democrat, they argue.

McDaniel lost to Cochran in 2014 in what was one of the nastiest primaries in recent history. He has positioned himself to the right of the mainstream wing of the GOP and does not support keeping McConnell as Senate leader.

Democrat Mike Espy, a former congressman who also served as agriculture commissioner during Bill Clinton’s presidency, has declared a “strong intention” to run for Cochran’s seat.

There will be no Republican or Democratic primaries in the lead-up to the November special election. If no candidate gets a majority, the top two finishers will advance to a runoff.