Vice president Biden did precisely what he should not have done: Open up more questions and create more problems for the president. The next debate will consist in large part of President Obama debating his vice president on everything from taxes to Libya. Obama is once again on defense with 3½ weeks to go in the race.

Mitt Romney lobbed the first grenade, rapping the White House for saying Biden spoke only for himself and the president personally when he said “we”didn’t know that the Libya consulate needed more security. In Virginia today Romney had this to say:

In the days ahead and in the next debate Romney will no doubt point out that Biden said the administration would raise taxes only on those making $1 million, but the president wants to sweep in those above the $250,00 threshold (including 1 million small businesses). Romney will no doubt make an issue about Biden’s false claim (which moderator Martha Raddatz challenged during the debate) that commanders had recommended the accelerated withdrawal date from Afghanistan. Even the New York Times knows that isn’t true.

I have no doubt that Obama will throw Biden under the bus, telling the debate audience Tuesday night that good ole Joe got it wrong. But at some point that highlights his own judgment in keeping a man so obviously out of touch (or lying) a heartbeat away from the presidency.

Biden helped aggravate another problem: Obama is losing his gender advantage with women. In the recent Fox poll, for example, Obama leads by only eight points, but trails by 10 points among men. In the Pew survey Obama leads among women by only four points, trailing among men by the same margin.

The conservative advocacy group Concerned Women for America is out with its poll, provided to Right Turn. That poll conducted by American Viewpoint on Oct.4-6 and 8 shows that in Colorado, Virginia and North Carolina Obama leads among women by only seven, down from an 18-point margin in September. Most interestingly, 49 percent of the women polled say that the federal government’s spending has hurt the economy and women chose Romney as the candidate who will best handle spending and debt by a 49 to 44 percent margin. The war against women has been a bust.

Biden’s smirking, obnoxious performance didn’t play well with women, both among pundits and in many TV focus groups. Obama can’t repeat that and must now go back, as he has done with his liberal base, to try to herd a traditionally pro-Democratic constituency back into his column. He can try doing that with hot-button social issues, but that creates problems with swing voters who are social conservatives.

In sum, Biden left a mess for his boss to clean up and did nothing to help boost the ticket’s appeal with a critical constituency it must win by a significant margin. Obama has no one to blame but himself. He could have put Hillary Clinton on the ticket.