WASHINGTON: Democratic White House contender Barack Obama has reversed a Republican surge in national polls for the presidential election swayed by the financial crisis and signs that Sarah Palin’s star may be dimming.

Obama, who has focused attacks on McCain’s capacity to rescue the US economy, led 49 to 45 percent in a new poll of likely voters nationwide by Quinnipiac University released late Thursday.

A CBS/New York Times survey put Obama up by 48 percent to 43 percent. The trend was confirmed in Gallup’s daily tracking poll, which had Obama ahead 48 to 44 percent, the first time in two weeks that the Illinois senator had a lead beyond the statistical margin of error.

A Pew Research poll out had Obama on 46 percent and McCain on 44 percent, while Rasmussen’s daily poll had the contest at a 48 percent tie nationwide ahead of the November 4 election, but again the trend was toward Obama, who had trailed by three points just three days ago.

Obama’s momentum set the stage for the first of three presidential debates with McCain next week and may represent the last chance to cement a lead in the tight race.

McCain’s selection of Alaska Gov. Palin as his vice presidential running mate electrified the conservative base and pushed the Republican into a poll lead which panicked some Democrats.

But Palin’s momentum seems to be diminishing.

“Sen. Obama is right back where he was before the so-called convention bounces with a four-point lead,” said Maurice Carroll, director of the Quinnipiac University polling institute. “The Democratic discombobulation after the selection of Gov. Palin as GOP running mate seems to be steadying.”

With economic turmoil ricocheting around the world, the Quinnipiac survey suggested economic arguments may be swaying support toward Obama.

In the poll, 51 percent said that McCain’s proposed tax cut will help the rich while only nine percent say it will aid the middle class. Thirty-three percent say Obama’s tax plans will help the middle class and only nine percent say it will benefit the rich.

The Quinnipiac poll showed that Obama led 54-40 percent among women voters, the key demographic, which Palin is targeting for Republicans.

He had a 91 percent lead among African-Americans and was the favorite of young voters and those over 55.