U.S. Rep. Vicky Hartzler has landed the endorsement of would-be colleague Josh Hawley in her 2022 Senate bid, support that one expert on Monday called “a shot in the arm” and another called “perplexing.”

Hawley announced his endorsement Saturday at Missouri State Lincoln Days in St. Charles.

“This is someone who understands the moment that we’re in, who understands the stakes that we’re facing, and who is willing to stand up and be a strong voice of the people of Missouri,” Hawley said of Hartzler, 61, who has represented a very conservative and mostly rural area of central and western Missouri in Congress since 2011.

She faces a crowded field of candidates that includes former Gov. Eric Greitens, Attorney General Eric Schmitt, fellow U.S. Rep. Billy Long and St. Louis lawyer Mark McCloskey, who gained attention in 2020 when he and his wife emerged from their home with guns to confront racial injustice protesters.

All are staunch supporters of former President Donald Trump, who has not made an endorsement, nor has he said if he will.

Hawley, elected in 2018, became a polarizing figure after he staged an Electoral College challenge to Trump’s loss in the 2020 election and raised a fist in support of Trump supporters just before many of them stormed the Capitol in January 2021.

Still, Hawley remains very popular among Missouri Republican voters, University of Missouri-St. Louis political science professor David Kimball said.

“I think it’s a shot in the arm, so to speak, for the Hartzler campaign,” Kimball said. “I think it can only help her campaign.”

St. Louis University political scientist Ken Warren called the endorsement “a little perplexing” since Hartzler is generally perceived as facing an uphill challenge, with Greitens and Schmitt seen as the frontrunners.

“Hartzler has very low name recognition,” Warren said.

Warren doesn’t believe the endorsement signals that the GOP establishment is falling in line behind a single candidate, rather than risk splitting the vote enough for Greitens to win the August primary.

Greitens resigned as governor in 2018 amid an investigation of an extramarital affair allegedly involving bondage and blackmail. A criminal charge was eventually dropped, but many establishment Republicans worry that if he wins in August, he could lose in the November general election.

Messages seeking comment from the Schmitt and Greitens campaigns were not returned. Long said in a statement that Hawley had told him on Wednesday that he was not about to endorse Hartzler, “so I am disappointed in him,” Long said.