Republicans are seizing on the individual mandate's penalty in the newly upheld health care law as proof President Obama broke his promise not to raise taxes on middle class Americans.

In the Supreme Court ruling on the law, Chief Justice John Roberts said the penalty on Americans who opt against buying health insurance is actually a tax, therefore making the individual mandate constitutional. Congress, Roberts reasoned, has the authority to assess taxes.

As it turns out the tax penalty in the president's health care law was modeled after the reform plan passed in Massachusetts under then governor Mitt Romney.

In a 2009 interview with CNN, Romney explained how the Massachusetts health care mandate worked. If the state's residents decided to forgo health insurance when they could afford it, Romney said they would face the loss of a tax exemption. In other words, they would be assessed a tax.

"There are a number of ways to encourage people to get insurance and what we did, we said 'you're going to lose a tax exemption if you don't have insurance,'" Romney told CNN in the interview.

The former Massachusetts governor said the mandate was necessary to achieve universal coverage in the state.

In order to qualify for the tax exemption, Romney added "...you gotta have health insurance because we want everybody in the system. No more free riders."

During the interview Romney held up his health care law as a model that "could inform Washington on ways to improve health care for all Americans."

Since then, Romney has said repeatedly his plan was meant for Massachusetts only.