ABC

After President Obama released his 2011 tax returns Friday, the pressure has been mounting for his Republican rival Mitt Romney to do the same.

The day after the president put out his tax information, Romney filed for a six-month extension on his own taxes, a move that Wall Street Journal editorial page editor Paul Gigot warned against today during the "This Week" roundtable. Gigot cautioned Romney not to "let it fester."

"I would have gotten the tax returns out three or four months ago or six months ago or a year ago," Gigot said. "I don't think you want that to be the focus of the argument."

President Obama is certainly aiming to put Romney's delay at the forefront of the general election debate, saying this weekend that Romney should "absolutely" make his taxes public.

"I think that it's important for any candidate in public office to be as transparent as possible, to let people know who we are, what we stand for, and you know, I think that this is just carrying on a tradition that has existed throughout the modern presidency," Obama told Univision in an interview that aired today.

But ABC's Cokie Roberts said Romney's bigger problem is not his tax rate, but his massive income. The former Massachusetts governor reported earning $21.7 million in 2010, but paid a mere 14 percent tax rate.

"We're not talking about his taxes, we're talking about how much money he has," Roberts said today on the "This Week" roundtable. "And he's very, very, very rich.  And he needs to find a way to talk about that so that voters don't - aren't turned off by [it]."

Romney campaign adviser Kevin Madden pointed out that the likely GOP nominee has already disclose d his estimated income for 2011 - about $21 million - and completed the "exhaustive" financial disclosure forms required for all presidential candidates.

"I think the more important debate that we're going to have is about what we're going to be doing with the American people's tax dollars when we get to Washington," Madden said.