Trump has inherited all this, and Barr knows all this. No post-Wilson president has been loyal to his oath to remain within the confines of the Constitution, because power by its nature expands. And power once given -- by Republican Congresses to Republican presidents and by Democratic Congresses to Democratic presidents -- remains in the presidency.
When Rome was threatened by serious invasions of pirates during the last days of the Republic, the Roman Senate gave near-dictatorial powers to the famous general Pompey, which he used to fight and defeat the invaders. When the wars were over, Pompey retained his powers. Cicero famously asked why the Republic repelled invaders so as to enjoy the rule of law only to give it away to a strong man. He complained that the Senate gave so much power to the general, it was now powerless to contain him.
And then, after Pompey passed his powers on to Caesar, the Republic ended and the imperial dictatorship began.
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