A few years ago I received a T shirt as Saturnalia gift. The shirt declared George W. Bush was a fascist and showed him with a scribbled in Chaplin moustauche. I never wore the thing, since I don't believe Bush was as bad as Hitler, just the worst president in my lifetime. Comparing Obama to Hitler is just ignorant, not racist.
I remember all that was said about John Kerry when he ran for president. Kerry, who was wounded three times and carried a fellow soldier to safety in Viet Nam, was branded a coward, traitor, baby killer, and other epithets all during the campaign. The swift boating of John Kerry serves as a baseline for how far Obama's critics can go without being racist.
Does the Tea Party have racist supporters? Absolutely-but so does the Democratic Party or almost any other political party with a majority of white folks. The Tea Party is just better suited to racist beliefs about big government favoring black and brown people over "full blooded Americans," but that doesn't mean a majority of people frightened by massive deficits, bank bail outs, taxation and government influence are being racist.