American voters back President Obama's decision to send 30,000 more U.S. troops to Afghanistan by a 19-point margin, 58-37 percent, the newest Quinnipiac University poll finds.

However, support for the president's war policy doesn't translate into their thinking he deserves the Nobel Peace Prize, which he is going to pick up on a trip to Oslo, Norway, this week.

In the poll out Monday, public support for the war in Afghanistan rose 9 percentage points, with 57 percent saying it is the right thing to do and 35 percent against it. Forty-five percent say they approve of the president's handling of the war, a 7-point increase from the university's Nov. 18 poll. Another 45 percent disapprove.

Sixty percent of voters say they also approve of plans to begin withdrawing troops in July 2011, compared to 32 percent who disapprove. But only 45 percent think the president will be able to keep that promise, while 40 percent express confidence Obama can remain on his timeline.

Since the last poll, Quinnipac has measured a rise in Democratic support for the war from 58-31 to a 46 percent split. Republican support climbed from 68 percent support to 71 percent.

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"President Barack Obama's nationally televised speech explaining his policy and troop buildup has worked, at least in the short term, in bolstering support for the war effort and his decisions," said Peter Brown, assistant director of the Quinnipiac University Polling Institute. "History teaches that the bully pulpit can be a powerful tool for a president who knows how to use it, especially when it comes to foreign policy."

On the flip side, 66 percent of voters polled said the president does not deserve the Nobel prize compared to 26 percent who do, and 41 percent said the choice of Obama diminishes their image of the award. Six percent said it makes them think better of the prize and 49 percent said it makes no difference.

Brown said in a written release that Obama benefits from a Nobel prize ceremony that occurs Thursday morning U.S. time, while most of the country is sleeping.

"Two out of three Americans don't think he deserves it compared to the quarter who do. Even among Democrats, only 49 percent think he deserves it, compared to 8 percent of Republicans and 19 percent of independent voters. As is the case with many questions related to the president there are wide gender and racial gaps."

The Quinnipiac University poll was conducted from Dec. 1 through Dec. 6 and measured opinions of 2,313 registered voters nationwide. The margin of error was 2 percent.