Watching the various campaign ads from both the Obama and Romney campaigns it's no surprise that the Obama ads are more negative than the Romney ads. After all, there's little in the way of accomplishments for Obama to campaign on. Even his "I got Bin Laden" claim doesn't really help. George H.W. Bush can attest to that as his popularity after the Gulf War was as high as any President, but he lost against Bill Clinton because he broke his promise on "No New Taxes". That's small potatoes compared to Obama's litany of broken promises.
For the most part Romney's negative ads are far more low key and sedate, with one run by the RNC closing with the statement "It's OK to make a change" after listing Obama's failures in office appear subtle compared with the Obama campaign's ads trying to pin all kinds of supposed inequities and crimes on Romney, all of which have been debunked by one of Obama's biggest supporters in the media, the Washington Post.
If Obama's lost the Post, then he's lost the campaign even before the two conventions have been held.
But as Glenn Reynolds has been reminding Romney and the GOP, "Don't get cocky!"