As I write, American conservatism has gone mad: openly, disturbingly and resoundingly bats. There is no mistaking it. But the furious imprecations and cracked laughter of the lunatic conservatives echoing loudly down the halls of our sad American bedlam have helped obscure the fact that liberalism in the United States is moribund.  While conservatives strive to tear down our rotten and unjust system and replace it with something even more terrifying, liberals offer nothing but a determination to patch up some of the superficial rot while approving the general injustice.

Entered in evidence: Paul Krugman takes issue with Peggy Noonan’s recent assertion that the Republican Party is a party of roiling intellectual ferment and new ideas, while the Democratic Party has nothing novel to offer. Krugman plausibly, though pedantically, resists seeing the radical right ideas of the contemporary Republican Party as genuinely new, since most of those ideas go back…