Whic is why I respect reviewers like Ebert and Kael. They may be dyed-in-the-wool liberal scumbags—but they know what they are talking about when it comes to film criticism.
I may find their politics despicable, but their writing is engaging and thought-provoking.
Not familiar with Kael, but I do find Ebert engaging to read. As you say, he's an out-spoken liberal and he does understand the structure of a good film. However, I take all his reviews with a salt tablet.
I can't fathom why he liked Sin City (and I should have known better, by the title alone) and while his review of Narnia is grudgingly positive, it reads as if he punted to keep his in-box from being flooded with hate-mail.