SALEM, Va. – With an eye on the Supreme Court ruling this week, Mitt Romney on Tuesday said President Barack Obama's time in office would have been wasted if the high court strikes down the president's signature health care overhaul.

The presumptive Republican presidential nominee previewed his health care strategy while speaking to supporters outside a Virginia machine manufacturer just two days before the Supreme Court was expected to rule on the constitutionality of Obama's signature domestic achievement.

"If Obamacare is not deemed constitutional, then the first three-and-a-half years of this president's term will have been wasted on something that has not helped the American people," Romney told more than 1,000 supporters gathered outside Carter Machinery in southwest Virginia. "If it is deemed to stand, then I'll tell you one thing, we're going to have to have a president — and I'm that one — that's going to get rid of Obamacare. We're going to stop it on day one."