First it was Sen. Bob Corker, R-Tenn. Then it was Sen. Jeff Flake, R-Ariz. Now it is Rep. Mark Sanford, R-S.C.

Clashing with President Trump is the quickest way to the exits for a Republican lawmaker who represents red-state voters. This is despite the lingering movement of conservative opposition to Trump that invites these politicians to assert their opposition to a president who lacks their shared history fighting for conservative principles.