I would write in Old Man Rogers.
Although I imagine his presidential tenure would be pretty much like Jimmy Carter's because he would care more about doing the right thing than anything else.
Other than that, it depends on circumstance.
We havent seen much fukkery with the MCU's version of Thunderbolt Ross's part yet except for his obsession with The Hulk in the Norton film. The Sokovia Accords was actually responsible in theory. He has a very presidential, commanding presence and an exemplary military career. His no bullshyt style would definitely win over Republicans who need a leader that allows them to make believe their tough.
Fisk would be an idiot to run instead of manipulating from the shadows. We only really know him as a crime boss in this iteration of the character. He should be moving like Giancana.
The MCU doesnt really have a Norman Osborne yet but if we go with the Sony version, I dont know how his psychiatric history doesnt come to light. Even with bullshyt medical records like Trump's, rumors are head and truth always comes to light. Plus Norman has about as much self control and stability as Kanye.
Then there's Loki. How are we playing this? Do I really have a choice if he's using God tier, supernatural trickery on me, an unsuspecting, unaware human? I'm fukked. We're all fukked. Unless Thor swings by and love taps him around, grabs him by the ear. dragging his ass to New Asgard.