Over at Volokh Conspiracy, Orin Kerr takes one commenter’s remarks on the treatment of Jose Padilla as an occasion to assert that “sarcasm is not an argument”:

The problem with sarcasm is that it pokes fun at the other side without actually making an argument. If you happen to agree with the speaker’s view already, this can be pretty entertaining: you don’t need an argument, so you enjoy the affirmation of how smart you are and how dumb the other guy is. But what if you don’t already agree? Well, in that case sarcasm doesn’t tell you very much except about the nastiness of the speaker. The sarcastic comment rather suspiciously avoids addressing the merits, and is more likely to turn off the undecided than persuade them.

Maybe. But in the instant case, I think the problem is that he’s citing a mediocre writer’s very clumsy, ham-handed use of sarcasm. It’s true that sarcasm typically implies an argument without actually making one, but this is often a feature, not a bug. The philosopher David Lewis used to say, to those who found his somewhat bizarre metaphysical views incredible, that he did not know how to refute an incredulous stare. But that’s just their advantage as a tactic in many cases: You can’t refute an incredulous stare. Think of how difficult it can be for conservative guests to debate Stephen Colbert, say. Part of the problem there is that you can’t react to his schtick as schtick without seeming humorless. But it’s also that you have to unpack the argument before you can get to responding to it. Obviously, it helps if the reader is predisposed to agree with you, but sarcasm well deployed can create the impression of a sound argument that, if stated more explicitly, might fall flat.