Paul Ryan is Mitt Romney's Vice Presidential choice.  As a consequence, there's been a good bit of attention paid to Ryan's much-touted appreciation of Ayn Rand.  One edge is to criticize Randian economic policy.  Another edge is to ask whether Ryan himself lives by the Randian rules.  Here's Joan Walsh taking the second option, over at Slate,  with her article, "Paul Ryan: Randian Poseur":

When his lawyer father died young, sadly, the high-school aged Ryan received Social Security survivor benefits. But they didn’t go directly to supporting his family; by his own account, he banked them for college. . . . After his government-subsidized out-of-state education, the pride of Janesville left college and went to work for government. . . .Let’s say it together: You didn’t build that career by yourself, Congressman Ryan.

It's been a regular question here at the NS whether some kinds of tu quoque arguments can be relevant.  Again, the best example is what we've been calling smoking dad, which has the father, in the midst of taking a drag from a cigarette, telling the son that he shouldn't smoke because smoking's addictive and bad for your health.  Of course, the father's a hypocrite, but he's right, and his hypocrisy actually is relevant, because it's evidence that the father, who thinks smoking's bad, can't stop.  So it is addictive.  OK, so what about Walsh's argument here?  It seems to be that: Paul Ryan is committed to Randian principles, but doesn't live by them.  So… what follows, and why?

Here's the argument with the strongest conclusion:  Ryan's failure to live by his principles shows that they aren't right, that they aren't practicable.  Randianism is all about individuals, doing things by themselves, and ensuring that others don't interfere.  But that's not how societies work. Instead, individual success arises out of large-scale cooperation, opportunities afforded, and others giving back. 

Now, I do think that the hypocrisy of those avowing ideology X can regularly be relevant to our estimation of X.  But not all hypocrisies are created equal.  Couldn't a defender of Ryan and Randianism say something like: sure, but all this is evidence of how things work now, not how they should.  Paul Ryan benefitted from this system, and it was in his interest to do so, but that doesn't mean that the system is just or appropriate.  It just means it benefits some people.  They should be free to criticize it, still.

I think that reply is just about right, but it does miss one thing, which I  think Walsh's column could make clearer: it's easy to forget, even when you're Paul Ryan, that individual successes are nevertheless social products.  And that social programs do help people, even Randians, pursue their self interest.