I have thought from the outset of the Tea Party movement that it would last three elections cycles.
That is the usual length of Know-Nothing movements. This is because when they succeed in electing some anti-politicians who vow to completely change the government, one of two things happen. Either the anti-politicians become normal politicians and compromise in order to accomplish a few things, or they become completely frustrated at their inability to change the entire government.
The main reason they can't change the entire government is that nearly everyone needs the government, including the Know-Nothings in their role as citizens of an actually functioning country.
And what happens after that is that the Know-Nothings become disgusted with their turncoats, or disheartened at their failures. Some of the movement diehards quit all politics in despair. Some of the single-issue activists give up on changing the whole system and focus on their single issue.
The third cycle of my three-cycle prediction will not be completed until next November. But yesterday's election was a portent of things to come. The Tea Party, as detailed surveys have shown, are not small-government libertarians. They are mostly traditional conservatives, fed up with the government subsidizing and encouraging people who they think undermine the nation. These include those with loose sexual morals; expensive, featherbedding government unions; and disorganized, poor voters. The Tea-Party-inflected state governments elected in the last cycle made laws or ballot measures suppressing all these kinds of bad citizens (from a Tea Party perspective).
But a majority of voters turned back all of these suppressive measures.
To me, that suggests that the tide has turned. The country has hit the rightward wall, and is beginning to turn back toward the center.