A majority of Americans, including almost a third of Republicans, say GOP presidential contender Mitt Romney should release more tax returns than the two years he has promised to disclose, a USA TODAY/Gallup Poll finds.
The issue is one Democrats have been hammering, including an open letter to Romney signed by almost two dozen mayors released Thursday that noted controversial disclosures in the 2010 return he already has released and demanded: "What else are you trying to hide?"
Those surveyed are divided on whether the likely Republican nominee is trying to hide anything. While 42% predict the release of additional returns would not reveal anything politically harmful, 44% believe it would include damaging information - including 15% who say they believe the revelations would be so serious that they would "show he is unfit to be president."
The national survey of 539 adults, taken Wednesday, has a margin of error of plus or minus 5 percentage points.
Romney has resisted calls to release more years of returns, noting that four years ago Republican nominee Sen. John McCain also released just two years of returns.
"We've given all people need to know and understand about our financial situation and about how we live our life," Ann Romney said in an interview Thursday on ABC's Good Morning America. Mitt Romney told National Review Online that Democrats are simply trying to get more details about his finances that opposition researchers can "pick through, distort and lie about."
Still, even some leading Republicans, including former Mississippi governor Haley Barbour, have advised Romney to defuse the issue by releasing more years of returns. Romney has released his 2010 returns and promised to release his 2011 returns.
"Public release of your tax returns is the only way the American people can know if they can trust your judgment, perspective and motivations," said the mayors' letter, signed by mayors from Los Angeles, Philadelphia, Milwaukee, San Antonio, Charlotte, Minneapolis and elsewhere.
In the poll, those surveyed:
• Are divided on whether presidential candidates in general should release their tax returns. Forty-seven percent call it "largely irrelevant" to helping voters decide who should be president while 44% say it provides "legitimate information that helps voters make better decisions."
• Agree by a substantial margin of 17 percentage points that Romney in particular should release more than two years of returns. By 54%-37%, they say Romney should release tax returns from additional years. Those calling for more disclosure include 75% of Democrats, 53% of independents and 30% of Republicans.
• Split along partisan lines about what sort of information might be revealed if he released more returns. Two-thirds of Republicans say the returns wouldn't reveal anything politically harmful, but a third of Democrats predict relevations that would show him to be unfit for the Oval Office.
"When it comes to candidates for the highest office in the land, Americans expect the opportunity to look under the hood and kick the tires," Obama campaign spokesman Ben LaBolt says of the survey results. "It's no surprise that they believe Gov. Romney should hold himself to the same standard as nominees of both parties have for decades."