Brendan Nyhan drops some actual political science and discovers that the Tea Party-powered GOP has actually produced more, not fewer, experienced candidates than the GOP of previous years.
[W]hile it's true that Tea Party candidates are less likely to have previously held elected office in more contested races, the differences are smaller than one might think -- 48% of non-TP challengers in competitive districts (25 of 52) versus 33% of TP challengers in competitive districts (18 of 54) and 53% of non-TP open seat candidates (15 of 28) versus 43% of TP open seat candidates (6 of 14).
In short, the Tea Party movement has affiliated itself with a surprising number of non-amateur politicians in competitive and open-seat races. As a result, the GOP still has a candidate quality advantage in the House races that matter most.
If this is surprising, a lot of that has to do with 1) a weird occasional media focus on noncompetitive races and 2) the ability of some smart politicians to brand themselves as "Tea Party" candidates. Marco Rubio, for example, could have run in a previous year as a savvy politician mentored by Jeb Bush. Instead, he introduced himself as the Tea Party in one man. Same happened with Ken Buck, a seasoned local politician who simply defined himself against a politician who'd held a higher office.
As to that first issue, I'm continually surprised that fringe candidates like Ohio's Richard Iott get so much attention; his penchant for dressing up as a Nazi is, of course, weird and stupid, but he never had a chance of winning. I'd add a bit to Nyhan's model, because the Tea Party has swung behind some first-time candidates in House races, mostly businessmen, who are going to win where token candidates used to lose.