The problem in this election cycle has been the failure of the Tea Party to come out early and in force behind a credible candidate. Romney has the inertia of having been runner-up in 2008. As the image above of Dole-McCain-Romney shows, many in the GOP have a tendency to back yesterday’s loser. It’s much easier than having to think about a new face. Only a concerted effort on part of the Tea Party could have blunted the “it’s my time” force of Romney and the GOP establishment. It’s a recipe for continued defeat and the Tea Party let the GOP get away with it.
There is no THE Tea Party. There is merely a very loose movement of very Right-wing people. The impulse that gave birth to the tea party (deliberately lower cased) is not new in American politics, but goes back many generations. It's like the tide, flowing in and out every so often, picking up new identifying labels like so much flotsam.
The tea party heritage goes back to at least the old America First movement of the 1930's, if not even further back. Ross Perot tapped into it in the early 1990's and helped get Bill Clinton into the presidency. We also had the militia movement during that period, until it died with Oklahoma City.
This old tide began to rise again in 2005 and might have peaked in 2010. We'll see. In the meantime, until it wanes again, it will help elect Democrats.