The first time Republicans toppled their own speaker during this Congress, it wasn’t a particularly edifying spectacle, but Marjorie Taylor Greene is reaching for new lows. To paraphrase Marx: first as a farce, then as a more preposterous farce. Greene made her anti-Mike Johnson case on Tucker Carlson’s show last week, and it was — as you’d expect — a stew of conspiratorial thinking and sophomoric ranting. You might say the anti-Johnson forces aren’t sending their best, but such is the weakness of their case that MTG is the best they’ve got. There’s a serious case against funding Ukraine, based...