GOP presidential candidate Rick Santorum joined the fray at the Supreme Court today, telling reporters from the front steps that frontrunner Mitt Romney is too compromised to lead Republicans on the most important issue of the 2012 elections.

The former Pennsylvania Senator, speaking during a news conference at the conclusion of the first day of oral arguments to determine the constitutionality of President Barack Obama’s health care law, attacked Romney over his Massachusetts health care law, which is similar to the federal law passed in 2010. Santorum said it is imperative that the Affordable Care Act be repealed and that only he is positioned to take that case to voters in the general election.

“We need someone in this race who can actually make a contrast,” Santorum said.

Repeating a line that has become a stump staple for Santorum, he said Romney is “the worst candidate to go against Barack Obama on the most important issue of the day.”

Like Obama’s health care law, the law Romney signed as Massachusetts governor includes a mandate to purchase insurance. From the outset of the campaign, Romney has vowed to repeal “Obamacare” and replace it with better reforms. Romney has said his state’s law was not intended to be a model for the whole country.