Which is to say, none at all. It’s really interesting in a sick, twisted way to watch economist Paul Krugman’s head go boom , as he sees his life’s work ignored when it is highly relevant to the circumstances at hand. So when he uses the term ‘flimflammer’ to describe supposed Republican intellectual heavyweight Paul Ryan, don’t kid yourself, he’s calling him a bullshitter.
And I agree with him completely on how one comes to that kind of judgment–after all, it’s very uncivil:

I decided that I would judge the character of politicians by what they say about policy, not how they come across in person. This led me to conclude that George W. Bush was dishonest and dangerous back when everyone was talking about how charming and reasonable he was. It led me to conclude that Colin Powell couldn’t be trusted, back when everyone said his UN speech clinched the case for war. It led me to conclude that John McCain was unprincipled and self-centered, back when everyone said he was a deeply principled maverick. And yes, it led me to conclude that Barack Obama was a good man, but far less progressive than his enthusiastic supporters imagined.

And so I don’t care how Paul Ryan comes across. I look at how he has gone about selling his ideas, and I see an unscrupulous flimflammer….
And about that Tax Policy Center report: it has been five months since that came out. Has Ryan tried, at all, to address the concerns the center raised? As far as I can tell, he’s offered nothing but vague assurances of good intentions. Why should we believe him? Because he comes across as a nice guy? So did Bush.

One of the worst things you can do as an observer is to become emotionally attached to what you’re observing. In the case of political reporting, this is rampant (think about the fawning over McCain when a bunch of reporters were invited to his house for BBQ). But Krugman is right, we should judge people by what they say and do in public, not whether they’re pleasant in private.
If this means calling people flimflammers–or fucking morons–so be it. Someone has to be accurate, if not civil.