Rob Portman and his old boss.

We'll learn relatively soon who'll be the Republicans' vice presidential nominee, but it seems pretty clear that Sen. Rob Portman (R-Ohio) will be in the mix. He's admitted to having undergone the vetting process, and he's been an active campaign surrogate.

But if he is tapped for the GOP ticket, Portman will face inquiries that might prove difficult to answer: weren't you George W. Bush's budget director at a time of enormous deficits and unprecedented fiscal irresponsibility? And weren't you also George W. Bush's U.S. Trade Representative at a time of a steep trade imbalance?

Democrats are already eager to paint a Mitt Romney victory as a third Bush term, and if Bush's former OMB director is on the ticket, that tasks becomes easier.

The senator is aware of the problem, and is taking steps to address it.

Sen. Rob Portman (R-Ohio), who served as former President George W. Bush's budget director, sought this week to distance himself from his former boss by saying he was "frustrated" in the high-profile post. [...]

Portman was careful to not criticize Bush while detailing the challenges he faced from other administration officials, whom he declined to name. The comments indicate that Portman is seeking to keep Bush at arm's length while also not appearing to be disloyal.

Portman did note, for example, that he was ultimately satisfied with the administration's second-term efforts to rein in spending.

"I was frustrated when I was there about some spending issues -- specifically, as you know, I wanted to offer a balanced budget over five years, and a lot of people didn't," he told The Hill, noting the decision to submit a balanced budget was ultimately the president's. "I prevailed. The president sent his budget -- not my budget, his budget -- a five-year balanced budget. But it was a fight, internally."

I see. So, Portman was a leading Bush administration official, but don't worry, he didn't much care for it. There's certainly no reason, the argument goes, to blame Bush's budget director for the flaws in Bush's budgets.

There seem to be two broad problems with this. The first, obviously, is that his efforts to distance himself from his own work in the Bush administration are kind of silly and literally unbelievable.

And second, Portman's spin doesn't exactly paint him in a positive light. He's effectively arguing, "Don't worry, I was completely feckless, so there's no reason not to put me one heartbeat from the presidency."