Frum believes that the tea parties will lose the GOP winnable seats:
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.
David Cameron's Conservatism responds to local British conditions. It's not an export product. But there is at least one big lesson that Americans could learn from him when the Tea Party finally ends: yes, a party must champion the values of the voters it already has. But it must also speak to the voters it still needs to win.