The law is not a strict list of all possible actions, activist judges are certainly an issue but they are uncommon and extremely rare at higher courts. Laws always contain grey areas and usually when a case actually gets before a circuit or higher court it's because a dispute has fallen into a grey area (or someone made an error and those are usually quick judgements). It's that grey area I'm talking about where decisions need to be made in accordance with legal intent.

Uneven application of the law is certainly an issue, and an overly wide application of the law usually falls under ex post facto laws which are seen as illegal by pretty much everyone. There are very sane people who can judge challenges to the law - we can lean on these people heavily.