It's worth remembering in this moment of global crisis that Donald Trump's first impeachment was the result of Trump's attempt to blackmail Ukrainian President Volodymyr Zelensky by withholding weapons and other military aid that Congress had already authorized.
Donald Trump did an enormous amount of harm. But he is a fool, and he could only do so much harm. If there is a really sophisticated person like a Ted Cruz or Ron DeSantis, then America would be in a much more difficult situation in terms of the country's democracy.
What is hard to legislate against is presidential corruption. Our system is not designed to have a corrupt president and that is where the existential dangers lie, as we saw with Donald Trump.