Updated

The Supreme Court is taking at a hard look at the constitutionality of President Obama's health care law this week.

Monday marked the first day of arguments and Republican presidential candidate Rick Santorum appeared outside the Supreme Court, making a case that he, not Mitt Romney, is the best candidate to take on Obama in the fall.

"There's one candidate who's uniquely disqualified to make the case. That's the reason I'm here and he's not," Santorum told reporters gathered outside the Supreme Court

Mitt Romney routinely says that he would repeal Obama's health care law if he is elected president. However, Santorum maintains that Romney is disqualified because of the health care law he put in place in Massachusetts when he was the governor of the Bay State.

"He is uniquely disqualified on the biggest issue of the day," Santorum told Fox News earlier on Monday. "On the one that pinpoints and summarizes all that's wrong with Washington, all that's wrong with government involvement in our life he can't make, in fact doesn't and won't make the case."

Santorum is also defending his run-in with a New York Times reporter on Sunday evening. The former Pennsylvania Senator was campaigning in Wisconsin where he said, "[Romney] is the worst Republican in the country to put up against Barack Obama. Why would Wisconsin want to vote for someone like that?"

Later a reporter from the New York Times asked him if he really thought Romney was the worst Republican in the country. Santorum looked visibly angry and told the reporter not to distort his words and called the question "bulls***."

Santorum is defending his remarks, "As a Republican candidate if you haven't, you know, blown off steam at a New York Times reporter you are not worth your salt," the candidate told Fox News Monday morning.