EXCLUSIVE: Peter Antico is fighting an uphill battle to become the next president of SAG-AFTRA, but he believes he has enough support from members to push him over the top when votes are counted Thursday. His supporters include Sylvester Stallone, Cuba Gooding Jr, Mickey Rourke, Andrew Dice Clay and Morgan Brittany. Long an outspoken critic of the union's current regime, he split from the main opposition group, Membership First, because he said they weren't doing enough…