The Tea Party was spectacularly successful in the midterm elections. They came from nowhere and won, or help to decide, dozens of races throughout the country. Because most Tea Party members are active and dedicated voters, unlike most political movements whose members are not committed voters, this movement shows all the signs of hanging around for a while. If their "elected members" can use the Tea Party base effectively not only will they grow in numbers over the next few years....they will , quite probably, prosper politically.
I'm not sure this answer is what you wanted to hear but to a political junkie the Tea Party movement is a fascinating study in grass roots political movements.