Missouri Attorney General Josh Hawley has formed an exploratory committee with the Federal Election Commission for a challenge to Democratic Sen. Claire McCaskill.

“Josh’s state campaign committee has ceased expenditures and the soliciting or accepting of donations while he considers becoming a federal candidate,” Hawley spokesman Scott Paradise said in an email, according to the Kansas City Star. 

[GOP Attorneys General May Shake Up Senate Primaries]

GOP donors and former politicians have been urging Hawley, who just won election last fall, to run for Senate. Rep. Ann Wager, the presumed front-runner to take on McCaskill, passed on a bid earlier this summer. Earlier this week, Wagner praised a kickoff event from state Rep. Paul Curtman, who has also formed an exploratory committee for Senate. Wagner has not made an endorsement and has spoken to many of the candidates considering a Senate bid. 

Hawley’s critics accuse him of hypocrisy, pointing to the 2016 campaign ad in which he criticized career politicians for using one political office to climb to another. The Missouri Democratic Party has already run web ads to that effect. 

[Attention Shifts to Josh Hawley in Missouri Senate Race]

McCaskill campaign manager David Kirby launched a similar attack. “Josh Hawley must want to set some kind of record — just a few months after promising Missourians he wouldn’t be a ladder-climbing politician, he decides he’d rather run for the next office than do the job he was elected to do,” Kirby said in a statement. “That’s exactly what Missourians can’t stand about politics — it represents the worst kind of politician, and calls into question what other promises Josh Hawley will break.”

President Donald Trump won Missouri by 19 points, making McCaskill one of the most vulnerable Democrats up for re-election in 2018. Inside Elections with Nathan L. Gonzales rates the race a Tossup.