Over the past month, the Republican Party has changed far more than I expected. First, the people at the ideological extremes of the party have begun to self-ghettoize. The Tea Party movement attracted many people who are drawn to black and white certainties and lock-step unity. People like that have a tendency to migrate from mainstream politics, which is inevitably messy and impure, to ever more marginal oases of purity.

Jim DeMint, for example, is leaving the Senate to go lead the Heritage Foundation. He is leaving the center of the action, where immigration, tax and other reforms will be crafted, for a political advocacy organization known more for ideological purity and fund-raising prowess than for creativity, curiosity or intellectual innovation.

Second, politics is being reborn. For a time, Republican candidates like Richard Mourdock of Indiana proudly declared that they didn’t believe in compromise. Political activists spent more time purging deviationists than in trying to attract new converts.

But that mania has passed. There are increasing signs that House Republicans are willing to unite behind Speaker John Boehner so he can cut a deal to avert the “fiscal cliff.”