By Shannon Bream

In three weeks, the Supreme Court will entertain arguments over President Obama’s health care law. At the heart of the entire law is the individual mandate, which requires every American to have health insurance coverage or pay a penalty.

Though Justice Anthony Kennedy is often viewed as the swing vote on the current court, the administration isn’t counting out the possibility it could win its case by persuading one of the so-called conservatives.

In its briefs, the administration has frequently quoted from a 2005 opinion written by Justice Antonin Scalia. In that case, Scalia wrote that Congress may use its authority under the Commerce Clause — pertaining to interstate commerce — to regulate an individual who wanted to grow medicinal marijuana at home and then sell it.

The Commerce Clause is, of course, the basis for the government’s position that the individual mandate is constitutional.

Elizabeth Wydra, chief counsel for the Constitutional Accountability Center, says Scalia’s own words make a powerful argument in favor of the mandate.

“Even if Scalia is skeptical of the merits of the health care reform law, it will be very hard for him to get away from his own writings on this issue that do support the government.”

But many doubters remain. Attorney Tom Dupree, former principal deputy assistant attorney general, is unconvinced that any of the court’s more conservative justices will be easily swayed.

“No matter how the administration tries to characterize this, at the end of the day, you’re talking about one of the most sweeping expansions of federal power in our history – and that’s something they’ve got to try to defend (against),” Dupree said.

The Supreme Court will not only consider the individual mandate, but also whether the rest of the law can survive if the mandate is struck down. It also will examine state objections to the expansion of Medicaid under the health care law. The arguments are scheduled for March 26 to 28.