Donald Trump wins reelection in 2020. Then in 2024, when he is Constitutionally ineligible to run for President, he is selected as the Vice- Presidential nominee by the GOP. The Republican Presidential candidate would obviously be a figurehead, overshadowed by the bigger-than-life Donald.
Since by then the Republicans in Congress and the judiciary and statehouses will have gerrymandered the local election districts so completely in their favor, that a victory in 2024 is easy to imagine.
Shortly after January 20, 2025, the Figurehead President , (an aged white man no doubt) , would resign, citing “health reasons” , and Vice-President Donald Trump becomes President-again.
The 25th Amendment is vague about all this and it would wind up before the Supreme Court, which by then will be completely packed with Trump appointees. They would rule for Trump, just like the 2000 Court, packed with Republican appointees, ruled for Bush.

Of course President Trump, Part II , won’t have much a country to rule over, as we will have devolved into a disparate and desperate society with street fighting and armed clashes –a civil war that makes the Lincoln –era Civil War seem like a schoolyard scrap. Russian will be the dominate global power, and in the U.S. there will the only the rich and everybody else. No unions, no middle class, no environmental protections, press restricted by the courts -it goes on and on.
This is how it happens, and don’t kid yourself that it can’t happen here.