Taking up the Republican Party's repeal and replace mantra, Mitt Romney on Tuesday fleshed out the health care reforms he would substitute for President Obama's 2010 overhaul.

After denouncing the Affordable Care Act as costly and unconstitutional, Romney told supporters in Orlando, Fla., that he would issue states waivers to opt out of the law. The alternative to the current Obama overhaul, Romney said, is a health care system governed by consumer-market principles.

If we do that and we stop making it like a big government-managed utility, we're going to see better prices, lower costs and better care, said Romney. 

Romney did back a popular provision in the current law, the one that prohibits insurance companies from dropping people with pre-existing conditions. But he said the protection should apply only to people who already have insurance, such as those who have to switch plans when they change jobs. That falls short of the Affordable Care Act's guarantee that insurance companies cannot refuse first-time insurance buyers with pre-existing conditions.

Let's say someone has been continuously insured and they develop a serious condition, and let's say they lose their job or they change jobs, they move and they go to a new place, Romney said. I don't want them to be denied insurance because they've got some pre-existing condition.

Romney also spoke of the need to address the country's large uninsured population, but he said responsibility for doing so should fall to states. He suggested diverting federal Medicaid dollars to help states cover uninsured residents. Romney has faced ample criticism for spearheading a Massachusetts law requiring residents to obtain health insurance, but he has defended his record by saying a law tailored specifically to Massachusetts was preferable to an all-encompassing federal approach.

I believe that states have responsibility to care for people in the way they feel best, Romney said. 

In order to help people obtain health insurance, Romney said he would pursue measures that give people more flexibility. He advocated offering individuals a tax break for buying insurance -- a benefit businesses currently enjoy when they insure employees -- and allowing people to buy insurance across state lines.