I notice a lot of his plans, even if by executive order, would be very hard to justify undoing.
Let's say if Trump got everything on his wish list, millions of illegals deported, built the Wall, Iceland, Canada, Panama and Gaza all territories the External Revenue service extracts trillions of dollars in tribute from, as well as tribute directly from NATO and UN to US, AND raping Ukraine for precious minerals to pay us back with interest instead of just a forever IOU, how would the next Democrat President justify undoing all that?
"Uh, I know America got rid of all the illegals leeching off the system, and is keeping more from getting in, freeing up funds for public services vastly, and we are now at our greatest territorial extent ever, bringing in more funds and resources, as well as trade and strategic security than ever before, but uh, we decided we don't like that, so come on back in Illegals! Come one come all, and we'll demolish the wall to let in even more than ever before, and even though we're bringing back in all those mouths to feed and more, we'll also be giving away all our new territories and all the revenue that came with them, and go back to going infinitely in debt forever to pay for illegals and every other country in the world!"
Then again, that's what happened to the British Empire