Exit polling showed that HRC once again won voters who decided in the last day - just like New Hampshire. In that race, the press was dancing over her grave in the 3 days before the primary.
We had the same thing after South Carolina, especially with the Kennedy endorsement. I am a big Kennedy fan and will be the first to tell you that he has been unfairly vilified by the media for more than a decade. The conservative media loathes him, and the MSM to be "balanced" always presents him in a pejorative light. But he endorses Obama, and every thing changes. He is now the liberal icon - the elder statesman of the party. Even David Brooks goes gaga over Ted Kennedy.
Voters are not stupid. They have seen Ted Kennedy unfairly pilloried for 10 years. He endorses Obama and he is transformed into the second coming of Abraham Lincoln. I suspect voters see this for what it is - the press piling on and trying to influence the outcome. Obama is dynamic and gets great press. Unfortunately for him, the press drives voters to Hillary when they cross the line and start shilling for him.
Full disclosure - I am a HRC supporter, but that is just the way I see it.