The Tea Party movement mocks educated reactions to its ire, so I'd like to start with a folksy observation. If it walks like a duck and quacks like a duck, then it's probably a duck. That duck can insist that it's something else -- say a patriotic, bald eagle -- but it's still web-footed waterfowl. In exactly the same way, the Tea Party movement claims to be something that it isn't.
1. Not A Tax Revolt. Federal taxes have not been lower at any time in the past fifty years; 47% of Americans don't pay any federal taxes at all. No one likes taxation, but it has been many generations since anyone has had less reason to complain.
2. Not Opposed to Big Government. The Tea Party movement generally favors Social Security, Medicare and the wars in Afghanistan and Iraq. The first two are positively socialist, and supporting nation building does not qualify as libertarian. Big government is fine when it works for them.
3. Not Inclusive. According to a New York Times/CBS Poll released last week, "...Tea Party supporters tend to be Republican, white, male, married and older than 45..." 90% of those polled think that Obama is a socialist; nearly one in five believe that he was not born in the US. Many also think that he's a cryto-Muslim. And the movement's 'ideological' leaders -- e.g., Anne Coulter, Sarah Palin, Michelle Bachmann, Rush Limbaugh and Glenn Beck -- all share a very pale skin color, as well as a incoherent demagoguery.
Rhetoric aside, the real purpose of the Tea Party movement is clear: prevent the sort of change that might threaten the privileges traditionally enjoyed by middle aged, white Republicans. These are the people who feel that the 'real' America is under assault by the poor, people of color, gay Americans and all immigrants. They wrap themselves in the rhetoric of democracy and tradition, but they are just elites trying to find an acceptable language with which to justify their fear and defend their self interest.
Unfortunately, "Securing Our Self Interest At Your Expense," isn't much of a campaign slogan. And so, we talk about Tea Parties instead.