Scott Vavrinchik is a partner in a company in Chicago that provides kidney dialysis services, which the federal government normally pays for.

“I think it is unconstitutional. I think it is a freedom of choice [issue]," he said. "Health care is not a right, it is a commodity.”

Attorneys-general in 26 Republican-led states, filed suit against the health care law. A Florida judge struck it down last year, though it has been upheld in other courts.

Maron Soueid, a recent college graduate from New Jersey, believes arguments against the law won’t stand in the long run.

“It has been difficult to find a job, and a job that will cover all of your health care, so this is definitely beneficial for a person like me,” Soueid said.

The Obama administration points out the law's benefits. On the president's re-election campaign web site a video highlights a family relying on it to care for a daughter with a heart condition.

“I can’t even fathom what is going through the minds of people who want to repeal the health care act," the daughter's mother says in the video. "They’re choosing life or death for many, many Americans.”

Health care is a key issue in the 2012 presidential campaign as Mr. Obama seeks re-election and spars with Republican challengers.

“Depending on what the Supreme Court rules, one side or the other could be particularly emboldened," said Henry Olsen, an analyst with the American Enterprise Institute. "It also brings back the conversation to health care, which is not a good field for President Obama to be fighting on.”