White House Hits Romney on Tax Returns and ‘Income Disparity’

His wealth and taxes suddenly a campaign focus, Mitt Romney said Tuesday he pays an effective federal tax rate of “about 15 percent.”

The White House, which expects the former Massachusetts governor to win the Republican nomination and take on President Barack Obama this year, had Press Secretary Jay Carney say the following:

This only illuminates what (Obama) believes is an issue, which is that everybody who's working hard ought to pay their fair share. That includes millionaires who might be paying an effective tax rate of 15 percent when folks making $50,000 or $75,000 or $100,000 a year are paying much more.

Watch Jay Carney field questions concerning Romney's taxes via CBS:

Romney was asked about his taxes shortly before he left South Carolina for a fundraiser in New York.

"What's the effective rate I've been paying? It's probably closer to the 15 percent rate than anything," Romney said. "Because my last 10 years, I've — my income comes overwhelmingly from investments made in the past, rather than ordinary income or rather than earned annual income."

By his own account, Romney hasn't received a regular paycheck since he left Bain Capital in 1999. Most of Romney's taxable income comes from investing the money he made there.

He donated income from his time running the Salt Lake City Olympics to charity. He also told reporters Tuesday that he has donated the proceeds from the sale of his book, "No Apology," to charity.

Romney told reporters he also received money from speechmaking before he announced his presidential candidacy early last year "but not very much." He provided no details, but in his financial disclosure statement, released last August, he reported being paid $374,327 for such appearances for the 12 months ending last February.

Romney said in the Monday debate he probably would release at least one year's returns in April because it's tradition.

"I have nothing in them that suggests there's any problem and I'm happy to do so," he said then. "I sort of feel like we're showing a lot of exposure at this point."

Some Republicans aiming to defeat him in Saturday's South Carolina primary are probably hoping he'll make his records public sooner than that.

"I think we ought to rename our flat tax. We have a 15 percent flat tax, so this would be a Mitt Romney flat tax and all Americans would pay the rate that he paid,” Newt Gingrich, the former House speaker who runs second in some polls in South Carolina, said. Gingrich is expected to release his own returns on Thursday.

Romney's remaining nomination foes emphasized in the debate in Myrtle Beach on Monday night that whatever vulnerabilities he might bring to a campaign against Obama, the party should know about them now. In the debate Monday night, Texas Gov. Rick Perry insisted that Romney release his returns, saying that the party needs to scrutinize its nominee now instead of later.

Does Gov. Rick Perry have a point?

With unemployment high and the country still struggling to recover from the worst recession in decades, Obama's re-election campaign has signaled it intends to "make income disparity a central part of this year's campaign," according to the Associated Press.

“It’s not for us to call on someone to release his tax records,” Carney said, “But it is an established tradition for presidential candidates to release their tax records.”

At the White House, Carney boasted that as a candidate in 2008, Obama released multiple years of tax records and has disclosed his returns annually since becoming president.

He said George W. Bush and Bill Clinton did the same thing, as did "nominees for each party for years and years and years." In a jab at the Republican front-runner, he said Romney's father, George Romney, released his own returns when he ran for the White House in 1968.

However, as a few analysts have pointed out, it may be unwise for this White House to bring up the topic of unreleased documents.

The Associated Press contributed to this report.