It's difficult for a political party to think strategically after a political defeat as severe as 2008's. But the Tea Party elevated the inability to think strategically into a fundamental conservative principle. Its militants denounce those Republicans who have resisted the movement as ideological traitors: "Republicans in name only" or even (charmingly) as "Vichy Republicans". In fact, the unthinking rejectionism of the Tea Party has strengthened Obama's political position. Now it threatens to deplete Republican strength in Congress, losing races that could have been won.