Wonkblog: Did Scott Walker bow out because people don't hate unions as much as he thought?

In this Survivor season of a Republican primary campaign, Wisconsin Gov. Scott Walker Monday became the second contender to depart the presidential island.Much has been written about the flubs and funding problems that took him from putative frontrunner to sharkbait in the span of weeks. They were certainly sufficient to tank a campaign, and perhaps they do tell us a lot about Scott Walker, the politician. But what does his short-lived run tell us about viewers -- the American electorate?