They are all guilty of something and NSA knows what those somethings are. Menendez is small potatoes compared to, say, Feinstein or Reid. Menendez spoke against the Iran deal and against the Cuba initiative. There are other Democrats who are uncomfortable with the Iran deal- several of the Jews and even others. Dumping on Menendez is a clear signal to the others of like mind. If JustUs will go after a minor malefactor like Menendez...
Obama can’t afford a single act of rebellion from within his own party because it might inspire others to do the same.
I agree that pretty much all are dirty to some extent which is why term limits are a good idea. The longer they’re in Washington the dirtier they get.