Batman is taking on The Joker as the race for the White House heats up in America - Michael Keaton has announced he's backing Barack Obama just days after Jack Nicholson confirmed he's supporting Hillary Clinton.

Nicholson has approved a pro-Clinton Internet video director Rob Reiner created using the movie veteran's most iconic film scenes, and now Keaton, who played the first big screen Batman, has admitted he wants Obama as America's next president.

He says, "There's something about him I find really attractive. (He's) really refreshing." And, as the two Democrats fight it our for their party's candidacy vote, Nicholson and Keaton aren't the only celebrities taking sides.