Republicans in Congress are retiring in historic numbers this year. Costello was one of the most blunt, but he's not the only Republican retiring from Congress to point the finger at Trump for their decision to leave politics. Even those who haven't explicitly said they are leaving because of Trump are arguably leaving in part because of Trump. The president's unpopularity in places like California, Washington and Virginia very likely factored into vulnerable Republicans' decision to step down rather than run for reelections they might not win. Rather inconveniently for Republicans, Costello is retiring after the filing deadline has passed, which means they will have to jump through hoops or even launch a write-in campaign to get a candidate in the race.

Source: Washington Post March 26, 2018 17:33 UTC