Off the top of my head I think most of the overtly "satirical" episosdes focus more on Lisa than Bart, since it makes more sense for her to be interested in politics (like the one where she goes to Washington and sees her congressman take a bribe from a logging firm).
Lionel Hutz was originally...
I strongly suspect that the sections of society in America who understand satire align perfectly with the equivalent sections in the UK. It's just there are a lot more Americans. And they're a lot louder.
The Simpsons, at it's peak over 20 years ago, definitely had a strong satirical streak.