83.7% chance Obama will win - NYT swing state analysis

In nationwide polls, the US presidential election remains a statistical dead heat.

One poll-of-polls has the candidates within 0.2% of each other.

But thanks to the opportunity afforded by Hurricane Sandy to show leadership (and garner praise from New Jersey's Republican Governor Chris Christie and New York's conservative mayor Michael Bloomberg), President Obama has increased his lead in the so-called battleground states that will decide the election under the Electoral College system.

A New York Times' calculation now gives Obama an 83.7% chance of winning - at least as the polls stand today.

Under the US system, each state is allocated a set number of "Electoral College" votes, on a winner-takes-all basis, pegged to population. So if Mr Obama wins a majority of the vote in populous California, for example, he would win its 54 Electoral College votes; if Romney wins Texas he will get its 34 votes and so on. 270 votes are needed to win the Presidency.

With most states safe Obama or safe Romney, the race comes down to a handful of toss-up states - easily the largest of which are Florida (with 29 Electoral College votes) and Ohio (18).

No Republican has ever won the presidency without carrying Ohio, and pundits say it will be difficult for Mr Romney to build the necessary 270 Electoral College majority unless he wins the state.

Mr Obama has maintained a small but persistent lead in Ohio throughout the campaign.

Now, according to the latest clutch of polls, including one by The Wall Street Journal/NBC and Marist (which has the President ahead 49% to 47%), Mr Romney has lost the lead he seized in Florida after the first debate.

A Politico.com swing state summary still has Florida in Mr Romney's camp:

Click to zoom.

But even if he carries Florida, Mr Romney is still behind 290 to 248, by Politico's count.

The New York Times, putting Florida into Mr Obama's tally, has the President ahead 305 to 232.

On Friday, New York Mayor Michael Bloomberg has written an editorial endorsing President Barack Obama - saying he is impressed with the President's response in the wake of Hurricane Sandy, and disappointed with Republican challenger Mitt Romney. 

Mr Bloomberg - who made his endorsement via the news service he founded - was elected Mayor of New York as a Republican, but re-elected as an independent. He claimed many independents shared his disillusionment with Mr Romney. Climate change contributed to Hurricane Sandy, Mr Bloomberg says, and Mr Obama is the candidate most likely to address the problem.

Mr Obama has also enjoyed the benefit of effusive public praise over his handling of the Sandy disaster from New Jersey's Republican Governor, Chris Christie - an earthy, popular figure on the right whom many Republicans had hoped would take a run at the presidency. 

And the New York Times reported this morning that another popular, high-profile Republican - Gulf War hero turned Secretary of Defense and Secretary of State Colin Powell - will shortly feature in a new round of TV ads for Mr Obama.