You could be forgiven for not knowing much about Mike Johnson, the newly elected speaker of the House. Most senators, including many Republicans, don’t know much about him, either. For example, Senator Susan Collins, the ranking member of the Senate Appropriations Committee, told a reporter that she had to google him. Senator John Barrasso, the third-highest-ranking GOP senator, said that he primarily knew about Johnson from what he had “read in the paper.” “I don’t know him,” Senate Minority Whip John Thune said on Wednesday morning. “May have met him, but that’s about it.” After Johnson’s election, Thune struck a...