Mitt Romney’s campaign has fired back at questions about his tenure at Bain Capital and his failure to release tax returns by blaming President Obama’s campaign for not wanting to talk about the economy. Given a chance to talk about the economy this morning, though, a Romney adviser failed to deliver specifics about how his plan would boost economic growth while also balancing the budget, as Romney claims he will do.

As ThinkProgress has noted, Romney’s plan to provide a massive tax cut to the rich would blow a hole in the federal budget Romney promises to balance by 2020. When MSNBC’s Luke Russert asked Romney adviser Tara Wall how Romney would offset the lost revenue, she failed to offer any specifics, telling Americans they could instead “research” his plan to find them. When Russert returned to the subject, Wall again failed to deliver an answer, saying Romney’s business experience is the reason he would balance the budget:

RUSSERT: What are the offsets? What are we specifically going to do to balance the budget?

WALL: Well, I believe Americans will hear a lot more about Governor Romney’s plan, and if you want to see in depth what his plan is, you can certainly research that and look at that more in depth. But overall, there have been a number of new regulations, over-zealous regulations, on small businesses enacted by this administration, and we have to look at those things. [...]

RUSSERT: Even with those small business cuts you’re talking about, they’re in the billions. We’re talking trillions with a T. Non-partisan: increase by the debt, Mr. Romney’s plan with these tax cuts, by $2.6 trillion. Why are there no specifics? You guys want to talk about big ideas, you don’t want to talk about Bain and the tax issues. I don’t want to talk about that. I’m asking you specifically: How does Mitt Romney’s plan balance the budget by 2020?

WALL: I think, if you look at the economic numbers, I’m not an economist and I’m not going to play an economist, I think that Mitt Romney has a proven record of bringing economies back. He brought down unemployment as governor, he created jobs as a governor, he was effective as a businessperson overall, and I think you have to apply those concepts. [...] You can’t discount that, and you can’t discount the fact that we have to be able to look at how we begin solving the debt problem and bringing that down, and to do that, number one, is to start with streamlining our tax code, bringing down our marginal tax rate, the regulations that have been overburdensome, and making real true spending cuts.

As they noted, the trouble with that is, Romney hasn't provided a plan with any specifics that would offset the tax cuts. We all know where he'd likely get the money, which is taking it out of the hides of the poor and the middle class. I'm sure he'd rather not put that in writing since it might harm his chances of being elected.