This is a fantastic article by Dan Boaz writing at Cato at Liberty. He examines several recent statements by liberals who charge opponents of health care reform as racists, and then, in the best argument I've seen that destroys that dishonest meme, Boaz calls on history and American tradition to debunk it:

The classical liberal ideas of individualism, individual rights, property rights, "negative liberties," and limited government date back hundreds, even thousands, of years. They find their roots in the Greek and Hebrew conceptions of the higher law, the Scholastic thinkers, the Levellers' ideas of self-ownership and natural rights, the political theory of John Locke, the economic analysis of Adam Smith, and the political institutions of the American Founding. To suggest that the case for freedom and limited government - or the application of that theory to contemporary proposals for the expansion of government - must be attributable to racism is uncharitable, ahistorical, thoughtless, and indeed contemptible.

It cannot be the case that every parody of a president who happens to be black is racist. And it is not good for democracy to try to counter every opposing argument with such a blood libel. The good news for advocates of limited government is that our opponents are displaying a striking lack of confidence in the actual arguments for their proposals. If they thought they could win a debate on nationalizing health care, or running trillion-dollar deficits, they wouldn't need to reach for such smears.