Well, My Mama Told Me there’d be days I’d run into people like you, who couldn’t even name nine, let alone The Tenth Good Thing About Barney. Ah well, some days are like that, even on the Straight Dope.
(I’m actually surprised to hear that Viorst is referenced at all! Some of the best books ever.)
Much tougher than it looks, I’d bet. First of all, in a court of law, pornography and obscenity have very different meanings; IIRC, the latter basically means ‘illegally pornographic.’ But nonlawyers sometimes use the two words interchangeably, and sometimes use ‘obscene’ to mean ‘smuttier porn than most’ and so forth.
And you haven’t even gotten to the issues yet; educating the public on basic definitions is just a prerequisite step.
Why would a judge recusing himself affect the government’s case? I just assumed that they would replace him with someone that isn’t a perve. 
If a judge dies during a trial, would that be any different?
It’s complicated because he declared a mistrial: http://bulk.resource.org/courts.gov/c/F2/953/953.F2d.240.91-3447.html
I happened to hear Michael Medved excoriating this judge a few weeks ago. Medved was scandalized and horribly disappointed that this “good conservative judge” would have some jokey, racy files on his computer. None of it sounded very shocking to me, but my understanding was that at least one video showed a guy being pursued by a sexually aroused horse. My impression was that it wasn’t pornographic, just a funny video of a dude tring to fend off an amorous horse, but since the case involved bestiality (and the question of whether bestiality is “obscene”), there was some question of whether that particular image constituted a conflict of interest. Medved thought it did and even called it “bestiality porn,” but I think it’s all much ado about nothing.
There has indeed been much ado, but I wouldn’t call it nothing. I think he properly recused himself and declared a mistrial. A judge must avoid even the appearance of impropriety, and IMHO it’s not kosher to have stuff like that on a publicly-available website (or wherever it was - I’m still not clear on that) in the judge’s own name (whether it was his son’s or not) while hearing a case on those very issues. The parties might reasonably question his ability to be fair and impartial, under the circumstances, and thus it’s better to err on the side of caution and let another judge take over the case.
I wonder what an appellate judge is doing presiding over a trial, anyway - he doesn’t have enough to do, running the Ninth Circuit and all?