Rolling Stone has been pimping for Gore all year with him on the cover a couple of times, Gore flying Jann Wenner (publisher) around on Air Force Two as a "journalist", and having a smash peace against Bush in every issue lately.
Anyone who's used Photoshop can tell what was done. Gore's khakis were kinda bunched up, so they used the smudge tool to add "definition" to the area. It's not like he's "A.G. Hammer".