Oddly enough, the image was created by history student (and Democratic Dennis Kucinich supporter) Firas Alkhateeb as simply an attempt to do something interesting with photoshop. The image was taken without permission, changed slightly (like adding "fascism"), and then became a popular among anti-leftists as a sort of shallow and unclear critique of Obama, or more obviously a guilt by association fallacy in picture form.
Obama Joker artist unmasked: A fellow Chicagoan | Top of the Ticket | Los Angeles Times