Peter Baker for the NYT:

The revolutionary hero Patrick Henry knew this day would come. He might not have anticipated all the particulars, such as the porn actress in the hotel room and the illicit payoff to keep her quiet. But he feared that eventually a criminal might occupy the presidency and use his powers to thwart anyone who sought to hold him accountable. “Away with your president,” he declared, “we shall have a king.”

That was exactly what the founders sought to avoid, having thrown off the yoke of an all-powerful monarch. But as hard as they worked to establish checks and balances, the system they constructed to hold wayward presidents accountable ultimately has proved to be unsteady.

Whatever rules Americans thought were in place are now being rewritten by Donald J. Trump, the once and perhaps future president who has already shattered many barriers and precedents. The notion that 34 felonies is not automatically disqualifying and a convicted criminal can be a viable candidate for commander in chief upends two and a half centuries of assumptions about American democracy.

And it raises fundamental questions about the limits of power in a second term, should Mr. Trump be returned to office. If he wins, it means he will have survived two impeachments, four criminal indictments, civil judgments for sexual abuse and business fraud, and a felony conviction. Given that, it would be hard to imagine what institutional deterrents could discourage abuses or excesses.