In his first trial Menendez was able to get a hung jury. Doesn't mean the DoJ was wrong to prosecute. I want prosecutors to be aggressive in pursuing criminals, especially elected officials. And I'm glad they got him the second time. The dude is clearly a crook. Adams is pretty much the same.
Now there are cases of prosecutorial misconduct. One involving a politician was against the late Ted Stevens, which a judge tossed.
But generally I have no reason to doubt the integrity of the DoJ. Trumpers of course have their own lens. In my view with Trump it is simply a case of the law very slowly catching up to a career criminal.