I realize it would be so much easier if the party elders could simply anoint candidates where there is no incumbent, and prevent incumbents from facing primary challengers. But politics is a messy business. It wouldn't be interesting otherwise. Like all political movements, the Tea Party will win some and lose some in these primaries. What I don't understand is -- if, as claimed, the Tea Party is irrelevant -- why do the moderates keep getting their panties in a bunch over it?
I do not consider myself a moderate, lest I'm compared to an extremist, and I don't get my panties up in a bunch over the TEA Party, but I do see a number of drawbacks.
They divide the GOP by campaigning as part of the GOP that's highly critical of the GOP, and in many cases making the case that there is no basic difference between the GOP and the Democrats, making them an insider outsider to the party. Whether you agree with that idea that there is no difference between the two or not is irrelevant, all I'm talking about is the impact that the TEA Party has on the GOP which may cause some members of the GOP to express concern.
They have been quite successfully demonized by the media. They are seen by many outside the GOP as racist extremists Neanderthals who wish to take us back to Antebellum times, desuffrage women and overturn child labor laws. They are not (obviously) any of those things, but in politics perception is reality, so even when a TEA Party member wins a primary, their presence on a ballot turns the general election into a battle against wild accusations and fabrications, and the actual issues are cast aside because the candidate has to spend an extraordinary amount of his or her time trying to convince people that they don't REALLY eat babies, leaving very little time for debate on things like the national debt, etc.
The TEA Party has an image issue, and until they deal with that, the most effective thing that they can do is negatively impact the RNC in elections... which coincides with the DNC's agenda. Making then unintended collaborators with the DNC.