Decisive? Per the national exit poll, O banked most of his margin before September, while he was busy methodically destroying Romney in attack ads, although his lead did noticeably widen in the final few days after a dead heat throughout October:

So maybe not decisive. But not helpful to Romney’s cause either:

Then, in the final week (October 29 to November 5), a noticeable change occurred: Obama’s coverage improved dramatically while Romney’s coverage stayed about the same but shrank in volume…

Not only did the tone change, but the amount of coverage changed as well. From October 1 to 28, Romney and Obama were both covered at roughly the same amount. Obama was a significant presence (meaning he was in 25% of the story or more) in 75% of the campaign-related coverage compared to 71% for Romney.

But in the final week, a bigger discrepancy was seen as Obama was a significant presence in 80% of the coverage, and Romney was a significant presence in 62%.

The data suggest two major factors in Obama’s increased and improved coverage in the final week of the campaign. One was the increase in amount of attention paid to the horse-race components of the race, which showed Obama with key advantages late in the race. During the final week, 46% of all press coverage of the campaign focused on horse-race and strategy stories, larger than the 39% that was devoted to such issues throughout the entire race.

The horse-race coverage was presumably driven by the final flurry of polls, most of which had O ahead. Nationally, NBC had Obama by one and ABC and Pew had him by three; meanwhile, the state polls had him leading in nearly every major battleground. There’s no way to know whether the rosy polling shook loose any undecideds for him or kept any Romney-leaning independents home, but seeing Pew’s numbers here made me think of Sean Trende’s piece in early October about how important it was to Obama’s campaign for them to be perceived as winning throughout the campaign. Trende’s theory was that if O lost the lead, the stench of a stagnant economy and leviathan deficits (political “gravity”) would suddenly overwhelm the conventional wisdom that he was going to win and that would cause him to fade. I do think that was a risk for him, but he averted it by having a solid second debate; if he had crapped the bed at that one too the way he did in Denver, Romney really might have vaulted ahead in the state polls and that would have been it. Or, given what we know now about Obama’s fantastic organizational effort, maybe I’m wrong and it wouldn’t have mattered much at all. Maybe a few more independents would have broken off for Romney but O still would have overwhelmed them by turning out endless waves of Democratic base voters. As it is, he ended up transforming the traditional likely voter model of election day into a registered voter model. The guy was making his own gravity.

Incidentally, here’s how things looked on Fox News and MSNBC the final week:

That’s right in line with how the networks skewed from late August to mid-October, replete with MSNBC out-tilting Fox, albeit even more dramatically in the last few days. Among the MSNBC shows surveyed by Pew, there was literally zero negative coverage of Obama and zero positive coverage of Romney, a result indistinguishable from propaganda. And this was while Benghazi news was still trickling out. To repeat a point I made in the post at the last link, MSNBC is less a liberal answer to Fox than it is a liberal answer to the left’s caricature of Fox.

Oh, the other major factor in Obama’s positive media coverage the last week, according to Pew? The hurricane, of course. But whether it was really “major” is unclear:

During the final week of the campaign, 4% of the newshole was devoted to stories focused on Hurricane Sandy, more than was devoted to other major issues such as Libya (3%), unemployment (1%), taxes (1%) and political endorsements (1%).

But of the 16 stories in the sample that focused exclusively on the hurricane and included Obama in a significant way, only 3 were positive and 5 were negative. (Romney was only a significant presence in two hurricane-focused stories-both of them neutral.)

The data suggest that the media did not run a huge number of stories focused on Obama and the hurricane and even those that did run did not offer a glowing review of the president’s performance. Instead, the storm may have had a more indirect influence on voters who saw passing references to Obama in other Sandy stories. If Obama was not present in 25% of a story about the storm, it would not appear in the data as an Obama related story.

So if, in the course of a long story about storm damage and clean-up efforts, a news outlet devoted a few lines to Chris Christie talking about the insane bipartisan awesomeness that is Barack Obama, that wouldn’t count for this survey even if it might count for a voter. Jim Geraghty makes a nice point too that Sandy preparation may have given disappointed former Obama fans just enough reason to feel good about him again. Think how many low-information voters — people who typically don’t watch the news — were watching during that last week to stay abreast of storm updates. Any time O stepped to a podium and made a statement about what was going on and what FEMA was doing to help, the networks featured that. They featured video of his “message: I care” disaster tour of New Jersey with Christie too. It may not have lost Romney any votes but it could have won a few for O that he was expecting wouldn’t be there this year. And yes, I realize I’ve already written a post that purported to debunk the “hurricane mattered” theory by noting the timeline of when O’s final poll surge began, but there might be a flaw in my theory. I pointed out last week that his numbers began to tick upward on October 26, three days before Sandy made landfall. That’s true — but it’s also true that Obama was making statements about the storm before it struck the coast, so in theory he was already earning message-I-care points with would-be voters. In fact, some quickie googling reveals one briefing as early as … October 26. I still don’t think the hurricane was decisive, but I’ve been fighting the feeling that it mattered at all and now, well…