Bob's blog: Romney can't dog tax question

Mitt Romney just can't seem to shake off questions about his tax returns, despite the fact that he's trying everything he can to not talk about it. He claims Democrats are just doing it for harassment, that they're trying to raise the issue as a distraction. But yesterday he was having this little news conference out on the campaign trail, had a big white board and he was ready to talk about the fine points of healthcare. Then one of the reporters asked if he'd ever checked back to see if he had ever paid less than 13 percent in taxes over the last ten years - and he said yes, I have. That suddenly took over the news conference and put the issue back front and center.

The Obama campaign said if that's the case, prove it. Release your income tax forms. Back-and-forth it goes.

Romney keeps saying he wants to talk about jobs and the economy. But since putting Paul Ryan on the ticket it's been all about Medicare and Ryan's budget proposals.

I would guess the Romney campaign is going to try and do some regrouping to see where they go from this. I don't think there's any possibility right now that he will release any more tax returns.

The Obama campaign really pounced on this one because they love it when the other side is talking about anything other than jobs and the economy.

It really doesn't hurt that when they're talking about Romney's taxes, somewhere in the story this 13 percent number always comes up. Of course most Americans pay a higher rate than that, and the Obama people try to use Romney as an example to show the tax code is unfair. They want to make this campaign about fairness, that rich people ought to be paying more in taxes. Every time Romney brings up 13 percent, it just fans the flames on this issue. I'll be talking to two top surrogates for the candidates, Senator Dick Durbin, D-Ill., and former Mayor Rudy Giuliani, R-N.Y. Giuliani had some harsh words about Vice President Joe Biden this week, saying Tuesday on CNBC that he's "just not very smart." I bet the two will have a lot to say about both Biden and Ryan.

I'm also really looking forward to my conversation this Sunday with a man who rules the debate, in a way, on taxes: Grover Norquist. I'll sit down with the mastermind of the anti-tax pledge that all but 13 Republicans in Congress have signed. I'll also be talking to Neera Tanden, the president of the Center for American Progress - an organization with a very different perspective than Norquist's Americans for Tax Reform group.

Plus, I've got a great roundtable to help break down the news of the week and offer their insight into what we should be looking for in the week before the Republican convention kicks off in Tampa. CBS Political Director John Dickerson, the Washington Post's Nia Malika-Henderson, plus Jeff Zeleny and Carl Hulse from the New York Times will all join us. We'll also talk to Kim Barker of ProPublica, an investigative journalism website, who will come on the show to share some new findings on SuperPacs with us.