Romney’s surprising stance is a result of the unusual nature of Lee’s main opponent, Evan McMullin. McMullin was recruited by anti-Trump Republicans to run for president in 2016 as a conservative alternative. He received less than 1 percent of the vote nationwide but received 21 percent in his native Utah, where many Mormons were aghast at Donald Trump’s character and views. McMullin is now running as an independent against Lee and seeks to bring together a coalition of Democrats, independents and disaffected Republicans to unseat the erstwhile conservative.

It should be a no-brainer for Romney to endorse his fellow Republican. Regaining control of the Senate is one of the GOP’s most important objectives, and that means marshaling every conceivable vote to make that happen. Lee is going to back whomever the Republican senators nominate to become their majority leader, but McMullin has not said which party he will caucus with if elected. Given that he has been endorsed by the Democratic mayor of Salt Lake County and other Democratic leaders, it’s an open question whether he will back the GOP.