Will appeared Sunday on ABC's "This Week" with a group of scholars, historians and writers who participated in a wide-ranging discussion about the government and the Constitution.
Will said Obama "has claimed for the federal government the power to do things that are simply unprecedented."
"Even the people who say that the mandates require American citizens as conditions of living in America to buy health care, no one denies that that's an unprecedented expansion of federal power," Will said.
Eric Dyson of Georgetown University said the Constitution has been "hijacked."
"I think that the Constitution is a powerful, living, vibrant document," Dyson said. "I think it's been hijacked by people with narrow, vicious and parochial visions. And I think the assertion that now we, of all people, this generation are somehow vulnerable to rebuff of the Constitution is like a Hagelian problem."
Harvard University history professor Jill Lepore, who is also the author of "The Whites of Their Eyes: The Tea Party's Revolution and the Battle over American History," said the Constitution has always been contested.
"Each generation of Americans struggles to inherit the mantle and claim the mantle of both the revolution and of the Constitution," Lepore said.
"What is actually to me been unusual about this political moment, is that a lot of people are trying to claim both the revolution and the Constitution," Lepore said. "The revolution is more often claimed by the left; the Constitution is more often celebrated by the right. The Tea Party movement has really embraced both, and in a certain kind of way collapsed the two, which is interesting as a historical phenomenon. But it's not -- it's neither novel nor sinister."