Mitt Romney steered his campaign message back in line with other top Republicans today, insisting that the health care law's individual mandate that requires most Americans to buy health insurance was "a tax."

"The majority of the court said it is a tax, and therefore it is a tax," Romney said in an interview with CBS Wednesday, citing the Supreme Court's health law ruling last week that the individual mandate fell under the federal government's authority to levy taxes and was therefore constitutional.

"They have spoken. There's no way around that. You can try and say you wish they had decided a different way, but they didn't."

Romney's comments came days after senior adviser Eric Fehrnstrom rejected the notion that the individual mandate imposed a "tax," saying instead that it was a "penalty."

"The governor believes that what we put in place in Massachusetts was a penalty, and he disagrees with the court's ruling that the mandate was a tax," Fehrnstrom said in an interview on MSNBC's Daily Rundown Monday.

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Romney, who contradicted Fehrnstrom's comments today, picked up a line of attack that many of his fellow Republicans had already launched at the president after the Supreme Court's ruling.

"The American people know President Obama has broken the pledge he made," Romney told CBS. "He said he wouldn't raise taxes on middle-Americans. Not only did he raise the $500 billion that was already in the bill, it's now clear that his mandate, as described by the Supreme Court, is a tax."

President Obama has called the price his health care law imposes on Americans who do not buy health insurance a "penalty."

"It was set up as a penalty for people who choose not to buy insurance, even though they can afford it, and for that 1 percent, we call it fair," White House chief of staff Jack Lew told ABC's George Stephanopoulos last Sunday.

Lew echoed similar comments Obama made in 2009 after Stephanopoulos asked the president if the mandate was a tax increase." I absolutely reject that notion," Obama said during the 2009 interview.

As governor of Massachusetts, Romney championed a health care law that imposed a mandate similar to that in Obama's health care law. Romney has insisted that the mandate he supported in Massachusetts was good for the state, but would not be good for the country.