In the larger political spectrum the answer is absolutely. If anything they contribute to their own defeats. Do the names Richard Mourdock and Sharron Angle ring any bells?
But can they be beat inside the GOP,that is another question. Despite the insurgent victories of tea party candidates in recent primaries, some Republicans now think they can take the party back. An AP story says the business community getting ready to support candidates against prominent Tea Partiers in Congress. In particular, they are going after Iowa Congressman Steve King, who is a Tea Party hero.
If they can knock him off it would show that the Tea Party doesn’t control the GOP.
Will it happen? Probably not.
Like most Tea Partiers, King is too popular with grassroots activists to be beaten in a primary. This is the real problem for more moderate voices in the GOP. They can’t win the primary but won’t defect in the general election. Looks like they are stuck unless something changes.