This is a conditional market. It will resolve N/A unless Trump is arrested AND >10% of the country thinks that his arrest is unjust + kept him from the presidency. The latter criterion will reflect consensus on American media, including Twitter and various news sites. If Trump is not arrested (based on https://manifold.markets/MartinRandall/when-will-trump-be-imprisoned), this will resolve as N/A.
Extreme civil unrest is defined loosely. I'll know it when I see it. Any of these would count:
> 10,000 deaths
Secession of a state
Wholesale replacement of a national / state legislature
Abduction of a prominent leader
EDIT 2023-08-29 22:35:00
Changed arrested -> incarcerated in the title.
To clarify further, I mean that Trump gets put under house arrest or in prison. Ie, his recent brief stint in jail does not count.