Ultimately any comment about the "Tea Party" has to have lots of qualifications because the TP isn't really centralized, hierarchical, or unified. Beyond common ideas about smaller, limited, accountable government, the Tea Party is different things to different people.
Some of the ideas and quotes that have given the TP a bad or controversial name may have come from some or a few TP-ers but not really define the whole TP. So, one can't fairly say that the TP itself is racist or xenophobic or defined by birthers or such, but one might say that the Tea Party harbors more than its share of people with these beliefs and that some TP leaders or groups are congenial to or guilty of them. Now, if you can demonstrate that leaders of say seven or eight or nine out of the ten largest TP groups have shown themselves guilty of something, then you could call that something a Tea Party characteristic.
But to say that everyone who goes to a TP rally or believes in their core economic and constitutional message is a racist is wrong, poisons civil debate, and makes the accuser sound guilty of the same intolerance of which she or he is accusing the TP-ers. Too bad life isn't simple.