AUBURN, Ala. (AP) — Alabama’s Republican primary for the U.S. Senate seat being vacated by retiring U.S. Sen. Richard Shelby has become a bitter high-dollar contest with the three strongest contenders jockeying for the nomination.

The leading candidates are U.S. Rep. Mo Brooks who won — and then lost — former President Donald Trump’s backing in the race; Katie Boyd Britt, the former leader of Business Council of Alabama and Shelby’s former chief of staff; and Mike Durant, an aerospace company owner best known as the helicopter pilot whose capture during a U.S. military mission in Somalia was chronicled in the “Black Hawk Down” book and subsequent movie.

Lillie Boddie, Karla M. Dupriest and Jake Schafer are also seeking the GOP nomination.

Observers say it’s hard to predict whether the nomination will be settled in Tuesday’s primary. The fractured field increases the chances that the race will go to a June 21 runoff, which is required unless one candidate captures more than 50% of Tuesday’s vote. David Mowery, an Alabama-based political consultant said the race has an up-for-grabs feel.

“It’s anybody guess as to who’s in first and who’s in second in the runoff,” he said.

As for the barrage of negative campaign ads in the primary’s closing days, Mowery said: “The gloves have come off.”

The Alabama race is one of several bitterly contested GOP primaries for open Senate seats. Retirements also sparked heated races this season in Pennsylvania, North Carolina and in Ohio. Trump further scrambled the Alabama race this spring when he rescinded his endorsement of Brooks. Both Britt and Durant have courted Trump’s nod, but he has so far stayed out of the Alabama race.

“We look at this country and don’t recognize it right now. Unfortunately, under the Biden administration, every single thing in this nation is moving in the wrong direction,” Britt said during a speech to the Republican Women of East Alabama.

Before leading the Business Council, Britt served as chief of staff to Shelby, one the Senate’s most senior members and a traditional Republican known for his ability to bring home federal projects and funding to his home state.

But in speeches Britt, running under a slogan of Alabama First, has leaned away from her hefty Washington resume. She said it’s important voters get to know her and kind of senator she will be. Her experience, she said, gave her an opportunity to understand how the Senate works.

“I can hit the ground running on day one. And for me, Alabama First is not just a slogan. It’s a mission,” she said.

Brooks, a six-term congressman from north Alabama, is banking on his long history with Alabama voters to overcome his feud with Trump.

“If you’re a conservative Republican I would submit to you that I’m the only proven conservative in this race. With me there is no rolling the dice to determine how I’m going to go on major public policy issues,” Brooks said, urging people to look up his ratings from the National Rifle Association, Heritage Action and other groups.

Despite losing Trump’s backing, he continues to run as “MAGA Mo,” invoking Trump’s Make America Great Again slogan, and his campaign website continues to include old video footage of Trump praising the north Alabama congressman.

Trump initially endorsed Brooks last year, rewarding the conservative firebrand who whipped up a crowd of Trump supporters at the Jan. 6, 2021 “Stop the Steal” rally that preceded the U.S. Capitol insurrection.

“Today is the day that American patriots start taking down names and kicking ass,” Brooks said. But Trump withdrew the endorsement in March after their relationship soured. Trump cites Brooks’ languishing performance and accused the conservative congressman of going “woke” for saying it was time to move on from the 2020 presidential outcome and focus on upcoming elections. Brooks said Trump was trying to get him to illegally rescind the election.

Trump has not made a new endorsement in the race. Both Durant and Britt have maintained they are the superior choice for Trump’s backing if the race goes to a runoff.

At a speech in Phenix City, a town in the shadow of the U.S. Army’s Fort Benning, Durant pitched himself as the outsider in the race. He began a speech by describing his combat service — which included not just Somalia but Desert Storm and missions in Panama — and then working in the defense industry and founding an aerospace company.

“I’m not a politician,” Durant said. “That is what people are tired of. That’s why people want outsiders. That is why people want straight shooters.”

Durant said his military experience separates him from those in Washington who “don’t know what they’re talking about” when discussing deploying troops.

“This is serious business. We don’t deploy troops, we don’t get in skirmishes, we don’t try to do nation building unless we truly understand the commitment that we’re about to make, not only financially, but the lives of young men and women, our national credibility, all those things that are on the line.”

Durant, a helicopter pilot who was held prisoner after being shot down, is seeking the endorsement of Trump, who once disputed that Sen. John McCain was a war hero because he was held as a POW. “I like people that weren’t captured,” Trump said in 2015. Asked about that, Durant said he thought the divisions between the two were “based on politics, not based on service.”

Both Britt and Brooks have criticized Durant for “dodging debates” after his campaign declined three separate dates offered by the Alabama Republican Party. Durant said he is willing to debate but could not make it fit his schedule.

Outside groups have pumped more than $20 million into the race to either support or oppose one of the frontrunners.

The Super PACS have been responsible for many of the attack ads in the race. Alabama Patriots PAC spent $4 million to support Durant after receiving money from America’s Project, a Virginia-based PAC associated with Jacob Harriman, a Marine Corps veteran who operates the organization, “More Perfect Union.” Alabama’s Future, a PAC opposing Brooks, has received $2 million from a Mitch McConnell-aligned PAC.

The Rev. Will Boyd, former Brighton mayor Brandaun Dean and retired Army veteran Lanny Kackson are vying for the Democratic nomination. However, Democrats have struggled in recent years statewide races in Alabama. Former U.S. Sen. Doug Jones, harnessed a well-funded campaign and a scandal surrounding GOP nominee Roy Moore, to win a special election in 2017. But Jones, who was the first Alabama Democrat elected to the Senate in over two decades, lost the following election.

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