9 October 2012 Last updated at 17:03 ET

Article written by Mark Mardell North America editor

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In-a-flap Obama turns to Big Bird

 

Critics say the use of Big Bird in campaign ads is a sign of Democratic desperation

The first opinion polls after the big debate have been published, and they make uncomfortable reading for President Obama.

There's no question that a huge majority thought he lost the debate with Mitt Romney, lost it clearly and badly. Let's say it again: it was the biggest defeat in the history of these debates.

The question now is whether Mr Obama's failure could cost him the White House.

The opinion polls right now do suggest that. The most dramatic is Pew, which gives Mr Romney a four point lead - last month they found Mr Obama had an eight-point lead.

If you don't trust such huge swings, Gallup gives Mr Romney 49% to Mr Obama's 47% among likely voters, but Mr Obama is leading in the same poll among registered voters.

Rasmussen has them level pegging on 46% among registered voters, noting sensibly, "since last week's debate, the numbers have shifted somewhat in Romney's direction, but even that change has been fairly modest".

Big Bird desperation?

All the usual cautionary words about polls and single events in election campaigns are worth restating:

Polls are only snapshots of a moment. What matters is a trend, not a single figure. If a poll's margin of error is 3%, a lead of 3% is fairly meaningless. Look at the difference between voters, likely voters and registered voters.

Then look at the swing states and the electoral college. There things aren't so grim for Mr Obama.

Still some, like Andrew Sullivan, are drawing dramatic conclusions from President Obama's drubbing. His column is headed: "Did Obama just throw the entire election away?"

Some accuse him of freaking out, but his fear reflects the anger and bewilderment of many Democrats.

Others wonder whether using Big Bird in an ad is a sign of Democratic desperation. That is rather over the top too: it's not chicken to run an internet advert that gets greater exposure because it's funny and the sort of thing people talk and tweet about.

It is not the main thrust of the Obama campaign's attack on Mr Romney: the main attack is that the Republican candidate is a liar.

The last deciders

They have to hit hard. My instinct is that the debate does matter. Think about who this is about.

There are now very few people left to be swayed. When you think about it, swing voters are very curious people. After months of the candidates insisting they have two very different visions of America, these voters still can't decide between two radically different ideologies.

So what matters to them must be character. If you are judging the candidates purely on the debate, purely on who you would want to argue your case if you were on death row, there wasn't much doubt who showed the most conviction and passion.

The Obama campaign accused Mr Romney of merely having a good "performance". But for swing voters, performance matters.

This time next week, the president will have a lot to prove.