Mark Williams, the tea party leader who wrote a blog post this week calling the National Association for the Advancement of Colored People (NAACP) racist, has been "expelled" from the National Tea Party Federation.

Williams wrote the blog post on Thursday in response to the NAACP's Tuesday declaration accusing the tea party movement of tolerating racist elements in its midst. It was written as an imaginary letter to President Abraham Lincoln and accused the NAACP of being racist for using the word "colored" in its name. When some reacted to it in outrage, Williams deleted it from his website, declaring it time to "move forward."

The National Tea Party Federation apparently decided to move forward without Williams. Spokesman David Webb said on Face the Nation this morning that Williams and his Tea Party Express had been pushed out because Williams' posting was "clearly offensive."

The tea party movement has been growing in influence in American politics since it began as a series of rallies in 2009. Candidates endorses by local and national organizations that are a part of the coalition have won surprising victories over establishment Republican Party candidates in states like Kentucky and Nevada.

Part of their challenge, however -- especially in handling broader debates about what they "are" -- is that there isn't a single Tea Party that speaks for all tea party activists. Rather, there are dozens of national and local organizations that loosely coordinate and all emerged in opposition to Wall Street bailouts and the growth of government.

National Tea Party Federation's expulsion of Williams and the Tea Party Express could be the first of many internal disputes to define the national tea party identity.