So instead of looking at the aggregate of polls, let's look at the trend within polls. It is a less hopeful picture. Below are several tracking polls and what they've been tracking. (The referent in each case is Obama, and the poll window is Feb 16 to March 2.)
Rassmussen: -3, -1, +4, +1See the pattern? Obama was behind, rallied to take the lead, and has seen his lead vanish over the past few days. If you include polling done only in the past four days, Obama is trailing slightly. Given that the polling actually reflects opinion a few days ago, this is not good news.
InsiderAdvantage: +1, -4, -5
ARG: +8, +7, 0
Survey USA: -5, +4, +1
There are a number of reasons why this is bad. It's bad because the way she's done it is to go negative. She's had a twin attack: denigrate his experience in cartoonish terms ("I have a lifetime of experience I would bring to the White House, I know that Senator McCain has experience he will bring to the White House, and Senator Obama has a speech he gave in 2002"), and smear him with scandal (Canada-gate and Rezko). She has very little chance to win the nomination on points--even winning the three states I expect her to tomorrow will give her a marginal return and leave her 140 pledged delegates behind--but she can do a lot of the GOP's dirty work.
The second problem with this outcome is that it will prolong the Democratic race into a death spiral, as an ever-more-desparate Hillary (no model of grace under pressure) gets ever more negative. Her only bet is to absolutely decimate the energy surrounding Obama and actually come close to him in pledged delegates (if she can get within 50 after 3200+ had been cast), she'll be in a position to argue to Superdelegates that it's a tie. And to win them over, she'll have to further stain him.
All of that results in a Democratic electorate who sits out '08. In numbers great enough to throw the election? Well, that's a prediction for later...