Rush Limbaugh is singing a song on his show called "Barack the Magic Negro" to the tune of "Puff the Magic Dragon." You can read about the song at the Media Matters website here and you can listen to it here. The last link is to the site "Crooks and Liars" which also reports that several employees at radio stations that air Limbaugh's show are complaining to management about Limbaugh's song.
In the Cleveland area Limbaugh is heard on WTAM, 1100. WTAM has a contact page on its website that lists its phone number and has a form you can fill out to send them an email message about their content, including Limbaugh's song. If you are so inclined please remember to be polite, be short, and avoid profanity. The contact page can be found here.
Progressives need to push back on this because if Barack is the Democratic nominee in 2008, Rush will try to use racism to defeat him, all the while complaining that whites in the Democratic Party are "reverse racists" for supporting him. The reason why we are sure that this will be his tactic is because that is his excuse for singing this song. He justifies it as a parody of the racism that exists on the left of the political spectrum.
There is also some real irony here. WTAM spends a lot of time talking about sports, especially professional sports. In Cleveland a lot of professional sports stars are Afro-Americans. So here you have a radio station on the one hand talking about say the Cleveland Cavaliers while on the other they are airing a show like Limbaugh's. They are using interest in black sports figures to make money and sell advertising while they are also using a person like Limbaugh and his racist song to make money and sell advertising. All apparently without one minute of shame or embarrassment.