WASHINGTON - New York Sen. Hillary Rodham Clinton has significantly widened her lead over Illinois Sen. Barack Obama in the Democratic presidential contest after a dispute over foreign policy, a new poll showed on Tuesday.

Democratic candidate U.S. Senator Hillary Clinton (D-NY) (L) responds to a question while U.S. Senator Barack Obama (D-IL) listens during the CNN/YouTube democratic candidates debate on the campus of The Citadel in Charleston, South Carolina, July 23, 2007. Clinton has significantly widened her lead over Illinois Sen. Barack Obama in the Democratic presidential contest after a dispute over foreign policy, a new poll showed on Tuesday. [Reuters]

The USA Today/Gallup poll of 1,012 adults showed Clinton's support at 48 percent among Democrats and Democratic-leaning independents, versus 26 percent for Obama. Former North Carolina Sen. John Edwards' support was at 12 percent.

USA Today reported on Tuesday the data showed Clinton advancing 8 percentage points and Obama falling 2 points from polling results from last month.

In a head-to-head matchup, the poll showed Clinton besting Obama 59 percent to 36 percent.

Among Republicans, polling data showed former New York Mayor Rudy Giuliani at 33 percent, former Tennessee Sen. Fred Thompson at 21 percent, Arizona Sen. John McCain at 16 percent and former Massachusetts Gov. Mitt Romney at 8 percent.

Conducted Friday through Sunday, the poll had an overall error margin of 3 percentage points.

USA Today said the findings seemed to reflect some success by Clinton in portraying her chief rival as inexperienced and naive on foreign policy.

In a debate two weeks ago, Obama said he would meet as president with such leaders such as Iranian President Mahmoud Ahmadinejad and Venezuelan President Hugo Chavez.

Clinton refused to make that pledge, saying, "I don't want to be used for propaganda purposes."

Both campaigns later spotlighted the exchange.

In the survey, Democrats and Democratic-leaning independents by overwhelming margins say Clinton would do a better job as president than Obama in handling terrorism, the Iraq war and relations with unfriendly nations.