Washington, Nov 2 (IANS): As President Barack Obama and Republican challenger Mitt Romney returned to the campaign in the wake of Hurricane sandy, new polls suggested a very close race though Obama appeared to have a very slight edge.

Buoyed by praise for his handling of the 'Frankenstorm', Obama Thursday ended a three-state swing with a rally in the battle ground state of Colorado where a CNN/ORC International Poll showed Obama with a 50 to 48 percent edge over Romney, well within the survey's sampling error.

An American Research Group poll conducted over the weekend had Romney at 48 percent and Obama at 47 percent, and an NBC News/Wall Street Journal/Marist poll conducted last week suggested the race was tied at 48 percent.

A Washington Post-ABC News showed 49 percent of likely voters across the country backing Obama to Romney's 48 percent. It's an identical 49 to 48 percent looking across eight states identified as "tossups" by The Washington Post.

Nationally, in 10 out of 11 releases of the tracking poll, the two presidential contenders have been separated by no more than a single percentage point, the Post noted. Seven times the gap between the two has been less than 1 percent, when looking at the fractional differences.

But the president continues to have a solid pushback to Republicans on the economy. By a 15-point margin (51 to 36 percent), more voters say former President George W. Bush bears more responsibility than does Obama for current economic problems.

But there's less of an apparent gap in the eight tossup states - Colorado, Florida, Iowa, Nevada, New Hampshire, Ohio, Virginia and Wisconsin - where 47 percent point the finger at Bush, 42 percent at Obama, the Post said.

Looking at 12 polls in Iowa, Nevada, Ohio and Wisconsin, FiveThirtyEight, an influential poll watching blog on the New York Times asserted Obama remains the favourite in the 538-vote Electoral College as it raised the President's share to 303.2 giving him an 80.8 percent chance.

But it also hedged its bets saying "Obama is not a sure thing, by any means."

Politico, another influential media site focused on politics gave Obama a 290 to 249 edge over Romney, while Real Clear Politics, a political news aggregating site showed the President edging ahead 47.4 to 47.3 per cent even as its kept intact its forecast of 206 for Obama and 191 for Romney with 146 too close to call.

Obama's campaign also got a boost with a fresh endorsement Thurday from New York City's independent three-term Mayor Michael Bloomberg and continuing praise from New Jersey's Republican Governor Chris Christie.

Meanwhile, former president Bill Clinton kept up his campaign blitz for Obama and other Democrats zig-zagging his way across the country. He has appeared at nearly 40 events for House candidates this cycle and raised $1.4 million for the Democratic Congressional Campaign Committee.