I dunno...a search of the Corporation For Public Broadcasting's website shows only a single program about schools with Bill Moyers, back in 1996, funded by public money (about $223,000). I know that most, if not all the money he makes comes from other source.
That said, it's somewhat difficult to figure out who funds what - the show itself appears to be funded by PBS, but individual programs appear to be privately funded.
What'd be really interesting to see is the grant applications to PBS - see if conservative program proposals are being turned down, or if they're just not coming in in the first place.
Snidely