"In accordance with precedents out there, it is constitutional," Obama said of the 2010 Affordable Care and Prevention Act passed by congressional Democrats with no Republican support. "That's not just my opinion, by the way, that's the opinion of legal experts across the ideological spectrum, including two very conservative appellate court justices that said this wasn't even a close case."
At a joint news conference with visiting leaders from Mexico and Canada, Obama was asked about the three days of high court hearings last week and subsequent speculation that conservative justices would rule against the health care law's individual mandate, which requires people to have coverage or pay a fine.
The measure is the signature legislation of Obama's first term as he heads into a re-election campaign this year. Polls indicate the nation is divided over the issue on ideological lines, with conservatives opposing the measure as a government overreach and liberals supporting it as a necessary overhaul of the health insurance system.
Obama on Monday framed the issue as one affecting everyone rather than an "abstract argument."
"People's lives are affected by the lack of availability of health care, the inaffordablity of health care, their inability to get health care because of pre-existing conditions," Obama said, later adding: "Americans all across the country have greater rights and protections with respect to their insurance companies and are getting preventive care because of this law."
In addition, the president noted, 30 million people will gain coverage when the individual mandate and the rest of the law are fully implemented in 2014.
"I think it's important and I think the American people understand and I think the justices should understand that in the absence of an individual mandate, you cannot have a mechanism to ensure that people with pre-existing conditions can actually get health care," Obama said. "So, there's not only an economic element to this and a legal element to this, but there's a human element to this and I hope that's not forgotten in this political debate."
Obama said he was confident the Supreme Court "will not take what would be an unprecedented extraordinary step of overturning a law" passed by Congress.
He also took a shot at critics of the health care bill, noting that such opponents now were calling for the kind of "judicial activism" they have opposed in the past.
"I just remind conservative commentators that for years, what we've heard is, the biggest problem on the bench was judicial activism or a lack of judicial restraint, that an unelected group of people would somehow overturn a duly constituted and passed law," the president said.
"I'm confident that this will be upheld because it should be upheld," Obama added.
The Supreme Court's decision is expected in June in the middle of the campaign for the November presidential election.
Conservative Sen. Orrin Hatch, R-Utah, hit back at Obama's comments later Monday, saying in a statement that "it must be nice living in a fantasy world where every law you like is constitutional and every Supreme Court decision you don't is 'activist.' "
"Judicial activism or restraint is not measured by which side wins but by whether the court correctly applied the law," Hatch's statement said, adding: "Unfortunately these attacks come as no surprise, since the memo appears to have gone out from the president's campaign that criticizing the Supreme Court is going to help his re-election."