The Assassination of Barack Obama Exhibit: Freedom of expression or racism?

A controversial art exhibit was raided and shut down before it could be viewed in NYC (June 2008).
According to the NY Times blog: Cityroom, Boston-born performance artist, Yazmany Arboleda, tried to set up a provocative art exhibition in a vacant storefront on West 40th Street in Midtown Manhattan with the title, ‘The Assassination of Hillary [...]