The mountains of negative, sleazy attacks directed at Mitt Romney finally came cascading down yesterday — on the Obama campaign. Sen. Harry M. Reid (D-Nev.) made up a tall tale about Romney not paying his taxes for 10 years. The Obama team launched downright false ads accusing Romney of outsourcing jobs. The campaign suggested that Romney might be a “felon” for misrepresenting his departure date at Bain. But it was a sleazy ad from the Obama super PAC suggesting that Romney killed a woman by leaving her with no health care that seemed to be the straw that broke the camel’s back and snapped the media’s patience. Bill Burton, an Obama confidante and super PAC chief, was dismantled bit by bit on CNN. Take a look:

No wonder the Republicans have pounced. The sleaze practically drips from the screen. (Notice how rudely Burton behaves when confronted by the CNN fact checker.) And while she explains that the woman had insurance, Burton keeps dishing dirt, insinuating that Romney (six years after he left Bain) deprived the woman of health care. As did Reid, Burton displays the very worst in presidential politics.

Throughout the day, Obama campaign staffers pleaded ignorance about an ad with which they clearly were acquainted.

Had the Obama team finally gone just a step too far into the mud? The hammering from the media gave the Romney team the opportunity to drag up all of the previous false ads and begin to ram home the case that Obama is a desperate politician with nothing to run on but unsubstantiated accusations and distortions. The left-wing spinners may try to minimize the self-inflicted damage or suggest that this is just one in a string of charges and counter-charges.

Regardless of the media take, however, voters must hardly recognize the “hope and change” candidate who ran against politics as usual in 2008. President Obama’s burn-down-the-barn negativity, devoid of restraint or good taste, is a far cry from the unifying image on which he built his career. Surely he thinks this will pump up his base doing this routine. But does he lose a moderate vote or cause a young voter to stay home for every vote he can round up from the base?

We’ll find out soon enough whether the “likability” advantage that Obama was peddling is being shredded — by his own attack strategy. And his media cheerleaders will need to decide whether his antics are, even for them, a bridge too far in the campaign battle.