A law school friend of mine sent me a message, relaying a question from one of his friends regarding the Tea Party generally and specifically if the movement was a Libertarian one. This is the slightly modified response I sent back. Please feel free to add your thoughts in the comments.
Perhaps it would be best to start by way of explaining what the Tea Party actually means. TEA Party is an acronym that stands for Taxed Enough Already. By default anyone who describes themselves as a Tea Party 'type' (active protester or supporter) believes that taxes are to high. Flipping that around, they must be an advocate for lower taxes. The desire or belief in lower taxes stems from fiscal conservancy.
While lowering the taxes would likely translate into increased revenue (as they have in the past) there is a simultaneous push for less government spending. We see the government flushing money down the toilet as it runs up unprecedented levels of debt. By its own predictions and metrics the massive bailouts/stimulus have been unmitigated failures. People were angry at Bush for spending more money then other president had; people are furious at Obama for spending enough money to make Bush look like a fiscal conservative by comparison. Furor increased by the fact that the money was a best wasted and at worst some sort of political kick backs; all done despite the clear will of the people to the contrary (just as with ObamaCare).
The Tea Party also references the famous event Boston. Fiscal Conservatives are not Anarchists and understand that government does have a legitimate place. They also understand that an overbearing government is a repressive government. Besides threatening our freedoms and civil liberties, it also acts as an anchor sinking business and hindering the economy.
While the Tea Party must be seen as fiscally conservative (which is the main stream position) it has been noticeably silent on social issues. This silence is intentional. While some Tea Party members have advocated for and against some social issues (think gay marriage, legalizing drugs, abortion...) there is no 'official Tea Party position' on those matters. The reason has two separate but equally valid reasons. The first is that there is no centralized Tea Party command which can dictate by fiat what those official opinions or positions are. The second is that the Tea Party did not start out to be a 'party' in the same way Republicans and Democrats are. The Tea Party started out as an expression of disgust over government taxing and spending run amok. To join was an expression of that singular set of beliefs; taxes are to high, government is spending to much, no bailouts, personal responsibility with full repercussions for choice (good or bad [side note: there is an understanding that the ability succeed necessarily requires a chance of failing]). While people joining have other beliefs, their beliefs in no way filter back to become Tea Party positions.
On the basic political spectrum a Libertarian is someone who is fiscally conservative and socially liberal. Technically the Tea Party can not truly be defined as Libertarian because they are silent on social matters. Libertarians however could correctly be described as Tea Party people along with Conservatives. The Tea Party can be seen as an alliance of Conservatives and Libertarians putting their disagreement on social issues aside to focus on taking back the country from the fiscal liberals and(/or) Socialists. The Tea Party does have a Libertarian feel. This stems from the embedded notion that Conservatives push social conservatism and Liberals push social liberalism; but while Libertarians may agree in principle with the Liberals on social issues they really do not push those notions on others. That is to say that Conservatives and Liberals try to legislate their beliefs while Libertarians want everyone to just leave everyone else alone. In that context the silence on social issues seems the Libertarian approach giving the Tea Party that Libertarian feel. Of course it is not true that all Liberals or Conservatives try to force their social views on others, but there is a prevalent notion that the minority of people pushing views on others is much smaller among Libertarians that either Liberals or Conservatives.