Flake. Corker. Romney. And now, Sen. Thom Tillis. The roll call of Republican senators in the U.S. Congress who have called it quits, rather than endure a political career sideways with President Donald Trump,

The North Carolina Republican had already made up his mind to leave the Senate, but the run-in with the president over Medicaid moved up the timeline of the announcement.

Even the most competitive and evenly balanced states are infected by the same contagion as the hardened one-party states.