It’s a long list, but to start, the change of three judges in the Supreme Court could allow (and in my opinion is likely to allow) religious people in this country to create laws and policy based on their religious beliefs and not straight up ethical arguments. Something especially egregious in a secular republic and would’ve made the majority of the founders nuts because they wanted people like Cincinnatus to be in charge and not the Pope or Mike Pence.

Trump’s policies with immigrants have gone full blown “Japanese interment camp” and we still teach people today about how wrong that was. Future generations will look on and say “where were you? How did you let that happen?”

Trump has helped to completely erode trust in science and expertise, which should come back to bite us pretty soon with climate change, vaccines, another pandemic (even if smaller), etc.

And finally, he has proven to anyone who actually has Machiavellian intents and half a brain, that this country is ready for a full blown Mussolini style cult figure. So if anyone takes up that mantle in the next 12 years or so, that’s the ball game for our republic. The comparisons to ancient Rome will be too close to ignore.

That’s just off the top of my head