Mississippi Governor Phil Bryant (R), shown in 2015, will appoint a senator to fill Republican Thad Cochran’s seat until a special election. (Mike Blake/Reuters)

An unusual Senate race that could split the Republican Party and imperil its majority is shaping up in Mississippi after Gov. Phil Bryant decided he will appoint a Democrat-turned-Republican to a soon-to-be-open seat.

Bryant intends to appoint Mississippi Agriculture and Commerce Commissioner Cindy Hyde-Smith, according to two Republicans familiar with the situation. She will succeed Republican Thad Cochran, 80, who has battled health problems and will step down from his Senate seat April 1.

Hyde-Smith is a former Democrat who served in the state legislature before being elected to head the agriculture and commerce panel in 2011. She would be the first woman to represent Mississippi in the U.S. Senate.

Republicans familiar with the situation spoke Tuesday on the condition of anonymity to describe private deliberations and a decision that had not been announced publicly. Representatives for Bryant and Hyde-Smith did not respond to requests for comment.

The likely appointment represents a new wrinkle for Senate Republican leaders and President Trump after last year’s loss of a GOP-held Alabama seat. Establishment support for appointed incumbent, Luther Strange, wasn’t enough, with conservative Roy Moore prevailed in the Republican primary. Moore, facing allegations that he pursued and sexually assaulted teenage girls while he was in his 30s, lost the general election to Democrat Doug Jones.

Trump and GOP leaders have defused other potentially explosive intraparty fights.

In Nevada, Sen. Dean Heller’s Republican primary challenger ended his bid at Trump’s urging last week. Before that, Sen. Bob Corker (R-Tenn.) declined to run for reelection, sparing the party a potentially destructive and expensive primary against Rep. Marsha Blackburn. Inside the White House, many of Trump’s political aides made it a priority to keep Corker out.

Protecting a razor-thin 51-to-49 majority and wary of insurgent conservatives who want to oust him, Senate Majority Leader Mitch McConnell (R-Ky.) has shown considerable interest in the Mississippi race. He privately urged Bryant, a fellow Republican, to appoint himself to the seat and then run for the remainder of Cochran’s term in a special election to be held Nov. 6.

But the popular governor ruled himself out earlier this month, leaving McConnell without the candidate he still believes, according to those close to him, would be best equipped to stop Chris McDaniel, a controversial hard-right state senator who announced last week that he would run.

Doubts emerged in mainstream Republican circles Tuesday about whether Hyde-Smith would be able to stop McDaniel if she runs in November.

Two Republicans, speaking on the condition of anonymity to comment candidly, expressed concerns that her past affiliation with the Democratic Party would give McDaniel fodder for attacks that could resonate with conservative voters.

McDaniel has been campaigning as a social and cultural warrior. He has pledged a hard line on “illegal aliens” and promised to fight for the Mississippi state flag, which incorporates the Confederate battle flag.

The campaign for Cochran’s seat could drive a wedge between Republican senators. Sen. Rand Paul (R-Ky.), a rebellious conservative, left open the possibility of supporting McDaniel on Tuesday.

“I don’t believe I’ve ever met him, but, you know, he’s been portrayed as the conservative in the race and we’ll be watching it closely,” Paul said.

McDaniel was an early supporter of Sen. Ted Cruz (R-Tex.) when he ran for president. Cruz would not say Tuesday whether he would back McDaniel, though in the past he has praised him.

Sen. Cory Gardner (R-Colo.), a top McConnell lieutenant who serves as chairman of the Senate Republican campaign arm, declined to say whether Hyde-Smith would be a good candidate. “You’d have to talk to the governor about who he’s going to appoint,” Gardner said. Asked whether McDaniel is a problem, Gardner said voters in Mississippi would have “plenty of options and good opportunities to win this election.”

Sen. Roger Wicker (R-Miss.) said he voted for Hyde-Smith twice. “If indeed the governor makes a statement tomorrow, I’ll have a statement to follow up,” he said as he walked into the Senate chamber. Asked whether he might support her, Wicker laughed and added, “I’ll have a very generous, positive statement to make about the governor’s decision.”

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.

While Mississippi leans heavily conservative, some Republicans fear McDaniel’s presence in the race could open the door to an upset by pushing centrist Republican voters toward the Democrat in a potential one-on-one showdown.

Former House Democrat Mike Espy, the state’s first black member of Congress since Reconstruction and a secretary of agriculture during Bill Clinton’s presidency, has declared a “strong intention” to run for Cochran’s seat.

McDaniel ran against Cochran in 2014 and lost in a runoff. The primary was one of the nastiest in recent history.

Initially, McDaniel announced he would run against Wicker this year. After Cochran said he was stepping down, McDaniel switched races. He did not immediately respond to a request for comment Tuesday on Hyde-Smith.

The winner of the special election will serve the remainder of Cochran’s term, which ends in January 2021.

Correction: An earlier version of this report mischaracterized Mike Espy’s role in the Clinton administration. He was head of the Agriculture Department, not an agriculture commissioner.