If the US falls into fascism rest assure other countries will follow suit. Europe will become more right wing and it will proliferate across the world. Wars, human rights abuses, and nuclear arm races will become more frequent. It will become chaotic. China will invade Taiwan. Russia will take Ukraine and come head to head with NATO. Israel will completely destroy and depopulate Gaza. Iran and Israel will most certainly go to war and the region on fire.
The US, no doubt causes a lot of havoc in the world but we are deterrent to a lot of shyt going haywire in this world. Any weakness we display on the national stage (like re-electing DJ) will encourage adversarial countries to take bold risks.
I've tried telling people this for a while.
All the evils in the world that are either perceived or real caused by the United States will be execerbated, not halted, in this new order. If this new order was promising freedom and protection of human rights, I would think differently. But when you see it being led by right leaning and authoritarian forces instead, that is bad news.
Most of human history has been in a state of conflict. Most people of the current generation in the west, have had the good fortune to live in relative peace. This is a period that is a exception. Folks don't understand some of the true horrors that can occur, but there is plenty of history that you can read to get a taste. They are happening places in the world right now, but during this generation most in the west have been protected from it.