What happened in Wisconsin signals a shift in political mood and assumption. Public employee unions were beaten back and defeated in a state with a long progressive tradition. The unions and their allies put everything they had into "one of their most aggressive grass-roots campaigns ever," as the Washington Post's Peter Whoriskey and Dan Balz reported in a day-after piece. Fifty thousand volunteers made phone calls and knocked on 1.4 million doors to get out the vote against Gov. Scott Walker. Mr. Walker's supporters, less deeply organized on the ground, had a considerable advantage in money.

But...