Republican presidential front-runner Mitt Romney used the second anniversary of President Obama's sweeping healthcare reform legislation to blast the measure as "an unfolding disaster for the American economy."

Writing in USA Today, Romney advocates for the repeal of the law and for allowing the states to individually develop their own healthcare plans. Romney argues that through tort reform and adjustments to the tax code, Americans would be better served.

"What we need is a free-market, federalist approach to making quality, affordable health insurance available to every American. Each state should be allowed to pursue its own solution in this regard, instead of being dictated to by Washington," Romney writes.

Romney also defends his healthcare plan, developed while he was governor of Massachusetts — a sticking point for many conservatives, who note that the program is similar in structure to Obama's signature legislation. The president has repeatedly said that the Massachusetts law was influential in shaping the federal legislation, and top Romney advisers worked with the White House on the legislation.

"When I was governor of Massachusetts, we instituted a plan that got our citizens insured without raising taxes and without a government takeover. Other states will choose to go in different directions. It is the genius of federalism that it encourages experimentation, with each state pursuing what works best for them. ObamaCare's disregard for this core aspect of U.S. tradition is one of its most egregious failings," Romney writes.

Romney hopes to rally skeptical Republicans around the idea that the Massachusetts plan was a "state solution to a state problem," and that "the reforms I propose for the country could not be more different than Barack ObamaBarack Hussein ObamaHolder: DOJ, FBI should reject Trump's requests The Hill's 12:30 Report — Sponsored by Delta Air Lines — Frenzy over Kennedy retirement rumors | Trump challenges DOJ Asian American and Pacific Islander community will be critical to ensuring successful 2018 elections for Democrats MORE's." But his Republican opponents continued to hammer him on the subject on the campaign trail Thursday.

"RomneyCare is a government-run healthcare program, it's mandates, it's fines, it's insurance exchanges set up by the government," Rick Santorum said while campaigning in Texas on Friday. "It's the template for ObamaCare."

Obama, in an interview published Thursday, accused Romney of "pretending" he had a different healthcare plan from the president's.

It was a 2009 Romney op-ed in USA Today on healthcare that became campaign fodder earlier this month.

In that op-ed, written as advice to the federal government while it was considering healthcare reform legislation, Romney wrote, "We established incentives for those who were uninsured to buy insurance. Using tax penalties, as we did, or tax credits, as others have proposed, encourages 'free riders' to take responsibility for themselves rather than pass their medical costs on to others. This doesn't cost the government a single dollar."

Santorum seized on those comments to say Romney favored the individual mandate that would require all citizens to buy healthcare — the core issue being challenged by conservatives in next week's Supreme Court hearing.

"Gov. Romney has been saying throughout the course of this campaign, 'Oh, I never recommended that they adopt my program in Massachusetts for an individual federal mandate; oh, I never did that,' " Santorum said while campaigning in Ohio, according to CBS News. "Oh, yes, he did. In a 2009 USA Today op-ed he recommended, he made suggestions to President Obama, including the individual mandate and taxing people who don't buy insurance. That is the individual mandate."