FWI: The next US president fixes everything Trump broke

In 2028, with Trump ineligible to run again and failing to cancel the election/make himself eligible to run again by modifying the constitution, two brand new candidates run. The one who wins (presumably the Democrat) goes on to become a president that totally rebuilds the US economy after the damage Trump did, strengthens the constitution, bans MAGA, and reverses harmful policies, this president is on Abe Lincoln/FDR/JFK level.

1) would this president be able to undo most of the damage to the US institutions within 8 years?

2) would it be easy or hard for the world to trust the United States again?

3) What safeguards would they put in place to ensure a President like Trump can never happen again?