It's not so easy to control because judges have to be re-elected or aspire to sit on higher benches and having police unions oppose you can make that more difficult.
There's a reason why there are more former prosecutors on the bench than former defense attorneys.
Judges don't make laws (well, at least, they aren't the ones I'm talking about with a jurisdiction-wide, state or federal, prohibition.)
Now, if you want to say that it's not easy to control because legislators and ultimately the electorate are biased toward and support this kind of police intimidation, that may be the case (though that's exactly saying it's not easy to solve because we, as a society, actively desire the status quo. It's easy to solve, it's hard to convince people it should be solved, which has always been the problem with civil liberties.)
Point of order: There's more former prosecutors on the bench than defense attorneys for a myriad of reasons, including financial (public service, bribes excluded, doesn't pay as well) and personal (there are honorable defense lawyers who believe the system is corrupt and want to make sure it doesn't win when it shouldn't).
The fact that they've pissed off the cops may or may not factor into it. Not saying you're wrong, just that it's not quite THAT simple.
There's a reason why there are more former prosecutors on the bench than former defense attorneys.