Of course the establishment Republicans look at some of the candidates the Tea Party put forward who didn't get elected, and say this is indicative that the Tea Party can have no political traction.
However, we never hear the establishment Republicans use the same logic against their own candidates.
John McCain was such a lackluster moderate Republican that his campaign was barely on life support until he picked Sarah Palin as his running mate. He still lost.
Mittens the Wonderhair was touted as the only candidate who could beat Obama, but he couldn't energize the base. Still, Obama won by only by a slim margin. Obama may have even lost if allowing for the rampant voter fraud in Ohio, Florida, and Pennsylvania.