The Constitution provides mechanisms for holding a president accountable.  Those mechanisms -- political and legal processes -- depend on the integrity of those who hold public office.  The reason that President Nixon was ultimately held accountable was that there were  Republicans in the Congress at that time who were women and men of integrity; who, as the facts and the evidence came to light, put country above party, patriotism (rightly understood) above personal interest.  As Trump embarks on the process of folding the presidency into his family and his corporate empire, he is well on his way to forming the most corrupt government in history.  At this writing, it's difficult to see any Republicans who will have the courage or integrity to object. I hope I'm wrong.