Republican U.S. presidential hopeful Rick Santorum was exaggerating on Tuesday when he said a healthcare plan that his opponent Mitt Romney put in place in Massachusetts put a big dent in his state's budget.

You expanded the pool of insurance without controlling costs. You've blown a hole in the budget up there, the former Pennsylvania senator said, lashing out at Romney at a Republican presidential debate in Las Vegas.

But according to a report by www.factcheck.org, the Taxpayers Foundation has said the Massachusetts law is not bankrupting the state.

In May 2009, the foundation put out a report called The Myth of Uncontrolled Costs, which concluded that the net added cost to Massachusetts taxpayers was $353 million in 2010, or roughly 1.2 percent of the state budget, it said.

Fellow Republicans have criticized Romney because the healthcare plan he helped develop in Massachusetts became a model for Democratic President Barack Obama's healthcare law. Romney defends the state law but has promised to repeal the federal version.

I'm sorry, Rick, that you find so much to dislike in my plan, but I'll tell you, the people in Massachusetts like it by about a 3-1 margin, Romney said in response to Santorum's remarks.

According to a recent poll by the Harvard School of Public Health and The Boston Globe, 63 percent of Massachusetts residents are in favor of Romney's healthcare plan. This is an increase from a 2009 poll that showed 53 percent of residents supported the plan.