The Tea Party didn't cause the Republicans to lose. In fact, Tea Party-backed candidates like Ted Cruz ended up winning, who *gasp* is Hispanic! Meanwhile, by playing "nice-guy moderate" like McCain and Romney. However, in terms of the primaries, while Romney was "knee-capping" opponents, the media certainly wasn't kind to Bachmann, Cain, and Santorum, and little could save them. Perry (especially Perry) and Gingrich self-destructed.
Really, the Tea Party is the only way to save conservatism, even if it means hijacking the Republican party (as the Democrat Party was hijacked by Socialists a long time ago)