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The White House and the Obama campaign today insisted that the individual mandate in the president's health care bill is a "penalty," not a tax, despite the Supreme Court's ruling to uphold the law under Congress' taxing power.

"For those who can afford health insurance but choose to remain uninsured, forcing the rest of us to pay for their care, a penalty is administered as part of the Affordable Care Act," White House Press Secretary Jay Carney told reporters aboard Air Force One today.

"You can call it what you want. If you read the opinion, it is not a broad-based tax," he said, stressing that the "penalty" would affect 1 percent of the population, based on CBO estimates. "It's a penalty because you have a choice. You don't have a choice to pay your taxes, right?"

The Supreme Court upheld the president's signature health care law Thursday, saying its mandate that virtually all Americans buy health insurance was legal under Congress' power to levy taxes.

While the ruling was a huge political victory for the president, that the mandate was deemed constitutional as a tax has provided Republicans with a new line of attack.

"The president of the United States himself promised up and down that this bill was not a tax," Senate Minority Leader Mitch McConnell, R-Ky., said Thursday. "This was one of the Democrats' top selling points because they knew it would never have passed if they said it was a tax. Well, the Supreme Court has spoken. This law is a tax. The bill was sold to the American people on a deception."

During his 2008 campaign Obama, repeatedly promised not to raise taxes on middle-class families and he adamantly denied that the mandate amounted to a tax on the U.S. people.

"For us to say that you've got to take a responsibility to get health insurance is absolutely not a tax increase," the president told ABC News' George Stephanopoulos in 2009. "What it's saying is, is that we're not going to have other people carrying your burdens for you anymore than the fact that right now everybody in America, just about, has to get auto insurance. Nobody considers that a tax increase. People say to themselves, that is a fair way to make sure that if you hit my car, that I'm not covering all the costs."

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In addition to the White House, the Obama campaign is also pushing the mandate as a "penalty" and not a tax.

"Whether you call it a mandate or tax, what it is is a penalty on the very few Americans who don't - who can afford health care, don't pay for it, end up in our emergency rooms getting free care and then we all pay for it in the form of premiums," Obama campaign strategist David Axelrod said this morning on NBC's 'Today' Show.

Massachusetts Gov. Deval Patrick, a top Obama surrogate, later rebutted the "bizarre attack" that the bill represents a tax increase on the middle class and urged reporters on a conference call not to believe "the hype the other side is selling"

Finding itself playing defense the morning after a huge political win, the Obama camp has embraced the ruling as an opportunity to hit rival Mitt Romney for championing a similar law as governor of Massachusetts.

"The penalty within the Affordable Care Act… is modeled exactly on the penalty that exists in the health care reform that was promoted and signed into law by Governor Romney in Massachusetts," Carney said today.

Furthermore, Romney has admitted that, not only does he "like mandates," but that the health law he ushered in as governor constituted a tax.

"You imposed tax penalties in Massachusetts?" ABC's Charlie Gibson asked Romney in January 2008.

"Yes," Romney replied. "We said, look, if people can afford to buy it, either buy the insurance or pay your own way; don't be free-riders."