"Above the Law?"

Dumocrats constantly ask if President Trump is “above the law,” but never have anything to say about their own “investigators” being “above the law.” The Constitution says that the accused may never be questioned without their lawyer being present to advise them if they ask for it, and must be advised (correctly) of their rights BEFORE any questioning. Any “evidence” obtained from them after they ask for a lawyer is inadmissible unless a lawyer is allowed, and PROVIDED if they cannot afford it. Why then, can the FBI place somebody in a room by him/herself, WITHOUT a lawyer, with eight Trump-hating FBI agents shouting inane questions from all directions? And why can they jump on a simple lack of perfect memory and call it a lie? Something for which the “accused” can be imprisoned? All this in perfect VIOLATION of the Constitution? Why can they intimidate Trump people time after time, “questioning” them for hour after hour, with the questioners working in “shifts” (so s not to tire them out), and not allowing the “subject” any rest periods or even bathroom breaks? All this with NO “probable cause” to believe there is ANY laws broken? Why is the Congress and the FBI “above the law” in their tactics while being able to charge those “subjects” with serious crimes if they show the slightest hesitation to “cooperate?” (Just common sense)