"Obama gaffe," "Romney gaffe," "Perry gaffe," "Biden gaffe" -- every party gets it equally. The word just means "embarrassing mistake," and I have literally never heard it used outside of the context of a meaningless, bullshit filler political news story. I'm not normally an angry man, but it's such an obnoxious word that if somebody at work used "gaffe" in a sentence I would fling my goddamned coffee into his face.
So for instance, during the health care reform debate, President Obama gave approximately 9 million speeches outlining how his plan supposedly would make the system more efficient. Then, in one speech, he stumbled, and instead of saying that the plan would rid the system of inefficiencies, he accidentally said it would bring inefficiencies. This slip of the tongue unleashed a torrent of headlines and blog posts and talk radio rants. On the other side, at a Mitt Romney campaign event, John McCain accidentally mixed up two words that implied Romney liked wasteful government earmarks. Boom! Gaffe!
"YOU'VE RUINED ME, OLD MAN!"
These are completely information-free news events, and they absolutely dominate political news coverage and analysis. It's like asking your doctor if the X-rays show a tumor, and all he'll talk about is how stupid the radiologist's haircut looks.