Capturing bin Laden would DEFINITELY change my vote...
...IF.... It's John McCain who catches him on video, gives him a good right punch, knocks him to the ground, rips off his beard, reveals Osama to be Barak Obama in disguise ("And I would've gotten away with it to, had it not been for you meddling old patriots!")....
...AND ONLY IF.... all this happens in space... on the moon, in front of a lunar lander (with a flag nearby, of course)....
(I don't believe the moon landings were fake, but it would so cinch the scene)Seriously, though, despite my uncertain opinion of the average voter, I don't think it would have much of a difference to the masses (unless, of course, one of the candidates is the one who actually captures him, as per my attempt at humor above). It might if this election was for Bush's second term, but I don't believe would carry over to any of the presumed candidates. And, as others have stated, it would raise a number of questions in regards to 'why now?', 'why did it take so long', 'Osama who-again?', etc. It could bring closure and provide a positive outcome on at least one of Bush's endeavors and provide for some legacy that wasn't as damning as many feel he'll leave the office with, but little else.
Capturing or killing bin Laden, despite fulfilling one of the goals of this 'war on terror', won't even help on that front unless one finds a means to sincerely and completely destroy his image before doing so. Otherwise you wind up just adding fuel to the fire.