President Donald Trump has suggested that Sen. John Thune (R-S.D.) should face a primary challenge in 2022, in an apparent response to Thune’s unwillingness to back a challenge to the 2020 election results. “Republicans in the Senate so quickly forget. Right now, they would be down 8 seats without my backing them in the last Election,” the president wrote on Twitter on Dec. 22. “RINO John Thune, ‘Mitch’s boy’, should just let it play out. South Dakota doesn’t like weakness. He will be primaried in 2022, political career over!!!” the president added, using the acronym for “Republican in name only” to refer to the No. 2 Republican in the Senate. Thune didn’t respond to a request for comment by press time. He told Newsmax on Dec. 21 that the plan by a group of House Republicans to challenge electoral votes during the formal count in Congress on Jan. 6 will …