PAUL KRUGMAN: Going to Extreme

Utah Republicans have denied Robert Bennett, a very conservative three-term senator, a place on the ballot, because he’s not conservative enough. In Maine, party activists have pushed through a platform calling for, among other things, abolishing both the Federal Reserve and the Department of Education. And it’s becoming ever more apparent that real power within the G.O.P. rests with the ranting talk-show hosts.

News organizations have taken notice: suddenly, the takeover of the Republican Party by right-wing extremists has become a story (although many reporters seem determined to pretend that something equivalent is happening to the Democrats. It isn’t.) But why is this happening? And in particular, why is it happening now?