"There is clearly a concern about executive power and the balance of power that comes out in a couple of different ways," said Joseph Torsella, president of the Philadelphia-based organization. The nonpartisan center is dedicated to educating the public about the Constitution.
Torsella said he believes the polls reflect long-standing skepticism of presidential power. "I think it's a basic chord in the American song and it gets louder and stronger depending on what's happening in the headlines," he said.
The survey also found overwhelming opposition to the government's power to take private property for redevelopment and to amending the Constitution to allow foreign-born citizens to be president. Americans are divided over government recognition of gay marriage, but younger people are far more likely to support it.
President Bush and Congress are at record low approval ratings in recent polls, with Congress even less popular than the president. But in the new poll, the public is more reluctant to expand the president's powers than those of Congress.
Two-thirds of Americans oppose altering the balance of power among the three branches of government to strengthen the presidency, even when they thought that doing so would improve the economy or national security. People were more evenly split over giving Congress more power in the same circumstances.
"The Constitution sets up three branches of government and to increase the power of one at the expense of the others endangers the fundamental structure," said poll participant James Crowder, 74, of Cockeysville, Md., a Baltimore suburb. "This current president and his vice president have distorted the office of president so much that it will take an enormous amount of time, if ever, for us to recover from that." Crowder is a Democrat and a retired Episcopal priest.
In one area, the poll found Americans clearly on Congress' side. They said Congress should have the power to require senior presidential aides to testify before House and Senate committees - a topic currently wending its way through the courts. The administration is trying to prevent former White House counsel Harriet Miers from testifying about the firing of nine U.S. attorneys.
The government's power to take private property for redevelopment had little support in the poll, not even when owners are paid a fair price and the project creates local jobs.
Participants said they consider private property rights conferred by the Constitution as important as freedom of speech and religion.
The Fifth Amendment allows the government to seize property for public use with just compensation.
In 2005, the Supreme Court ruled 5-4 that governments may seize people's homes and businesses - even against their will - for private economic development when there is a corresponding public purpose of bringing more jobs and tax revenue.
In the new poll of people's views on the Constitution, 75 percent disagreed. Opposition to the government power known as eminent domain was as strong among liberals as conservatives.
Cities, backed by some liberals, generally see the power to seize private property as an important tool for urban renewal projects crucial to revitalizing cities.
Many conservatives - particularly in the West - have called the high court decision a dangerous interpretation of the Constitution that would lead to abuse of individual rights.
Since the ruling, 39 states have enacted legislation or passed ballot measures restricting the government's power to take property, according to the National Conference of State Legislatures.
The poll also found a split on whether governments should recognize gay marriage. But a majority said same-sex couples should be entitled to the same benefits as married, heterosexual couples.
The answers to these questions revealed a sharp generational split. More than two-thirds of people under 35 favor recognition of gay marriage, compared with less than 40 percent of those 35 and older.
Majorities also favor following the rule of law, even if that sometimes comes at the expense of short-term public safety considerations and protecting the rights of everyone in the face of majority opposition.
The public broadly supports government aid to religious organizations for social service programs. But that support drops sharply when organizations also promote their religious beliefs while providing help to the homeless and other social services.
The AP-National Constitution Center poll involved telephone interviews with 1,000 adults nationwide. The survey was conducted Aug. 22-29 by Abt SRBI Inc. and had a margin of sampling error of plus or minus 3.1 percentage points.