I still can’t believe this RINO won his primary against a field of 6-8 tea party candidates in 2014 when EVERYONE knows this guy is a stinking RINO.
That's the problem - too many opponents. If it had been one or two, he'd have lost. With a field that large, the names become obscure and people tend to go with the familiar, warts and all.
The big problem is that there is so much infighting among “tea party” candidates that no single candidate can ever get enough support to make a difference. Republicans in general have a lot of trouble working together, and the more conservative groups seem to have the most trouble of all: for every single one, it’s “my way or the highway,” and each voter practically has his own candidate. And there’s no big picture, that is, no strategy in the choice of candidates.
Part of this is because many of these candidates are political amateurs and, of course, another part of it is that the GOP establishment doesn’t take them seriously because they don’t have much ability to network, raise money, etc. More political savvy would help; you can’t expect virtue alone to get you elected, alas. But nobody seems to learn from past errors: they just get mad and stalk off.