You live in a republic with a supreme court, congress, and elected president. You wake up one morning to find that the president had fired congress and the court.
I’d be a bit shocked as a President of the USA would need the military and probably also federal law enforcement on his/her side. So a takeover of this sort would be truly astonishing.
I’d let it go for a few days, maybe a few weeks, to make sure who in the country was supporting the take over... they would be the enemy of our country along with the president, military and federal law enforcement.
Then I’d meet up with a few people I know and begin a resistance campaign... which would not be peaceful.