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.

Sen. Thom Tillis’ decision not to seek reelection is jolting what was already expected to be a fierce battle for his seat, which will now be wide open in 2026.