If you think today's political ads are negative, check out some historical political tv ads. Here, for example, is perhaps the most famous ad of all time, the Daisy Girl ad, created by the ad agency DDB and run just once on TV by Lyndon B. Johnson against Barry Goldwater.
LBJ crushed Goldwater in the election.
Of course, while McCain hasn't shown an ad with Obama flying a plane into the Empire State Building, we still have a week and a half to go and McCain just had his worst polling day yet. If the McCain campaign goes that route, I suggest Obama run an ad of McCain wandering around the White House in his pajamas, drooling and mumbling incoherently, while elsewhere Palin stands in her enormous walk-in closet flipping through one of several hundred designer suits mumbling, "Ooh, you betcha!"