Sens. Hillary Clinton and Barack Obama appear at the YearlyKos presidential forum in Chicago Saturday.
The survey, following a high-profile spat between the two candidates over who is better suited to handle foreign policy, shows Clinton at 48 percent -- a 22-point lead over Obama. Clinton's support is up 8 percentage points from a similar poll conducted three weeks ago, while Obama, at 26 percent, is down 2 percentage points. Former North Carolina Sen. John Edwards stands at 12 percent.
"[Voters are] taking a good hard look at all the candidates and concluding that Hillary has what it takes to be president and what it takes to take on the Republicans," wrote Mark Penn, a top strategist to the New York Democrat, in a memo to supporters Monday. "They know that Hillary Clinton has the experience and strength to bring about real change." Watch what the numbers mean »
Clinton's boost could be the result of the two candidates' recent quarrel over one of Obama's answers at the CNN/YouTube Debate last month. Obama said he would meet with world leaders openly hostile to the United States during his first year as president, while Clinton said she would only do so after a set of preconditions had been agreed to.
Clinton later called Obama's answer "naive" -- a critique that may have struck a cord with her party's base. Democrats and Democratic-leaning Independents now significantly favor Clinton to handle terrorism, the Iraq war and relations with "nations that are unfriendly to the United States."
Meanwhile, Obama's campaign sought to reassure supporters Monday that the Illinois senator remains a top Democratic frontrunner in the White House race, calling national polls "irrelevant."
"While the Washington insiders focus on irrelevant and wildly inconsistent national polls, there are strong signs in Iowa, New Hampshire and South Carolina of the growing power and potential of this candidacy," David Plouffe, Obama's campaign manager, wrote in a memo.
In addition to the latest USA Today/Gallup poll, two other recent national polls indicate a large gap between Clinton and Obama. A Newsweek poll suggests Clinton holds a 23-point lead, while the latest NBC News/Wall Street Journal poll put the lead at 21 points.
In early primary and caucus states like New Hampshire and Iowa, however, some polls show Clinton, Obama and former Sen. John Edwards virtually tied. And other state polls show Clinton with a lead, but one far smaller than national surveys like the latest USA Today/Gallup, Newsweek and NBC News/Wall Street Journal polls.
"We fundamentally reject the importance of these national primary polls," Plouffe added. "This is a sequential process that begins in Iowa and carries through the calendar. If national polls were affecting our ability to grow the campaign, perhaps we would pay them some attention. But they have not, so we don't."
The poll also measured a stable Republican race, registering former New York City mayor Rudy Giuliani at 33 percent, former Tennessee Sen. Fred Thompson, not yet a declared candidate, at 21 percent, Arizona Sen. John McCain at 16 percent and former Massachusetts Gov. Mitt Romney at 8 percent.The poll, conducted August 3-5, surveyed 490 Democratic leaning voters and 405 Republican leaning voters. It carries a margin of error of plus or minus 5 percentage points.