Openly broken and divided, running ramrod into either a civil war, civil insurgency, or actual fascist rule. There can be no amicable "American Divorce" since the left wants absolute total control of everything involved, and would refuse to give up power which such an event would require. Neither will they come to heel without violence.
There is an offshot possibility of the right finding its balls, putting a kabash on the worst of it, and creating only a left-wing insurgency movement for a decade or two. The movement from the populace wing is promising and has remained consistent, but it won't be truly tested until it both has a trial by fire in the 2022 midterms and it is seen how they use the power gained from such.
If they fail to perform adequately, I really can only see two results. Civil War if the Democrats retain power, or someone a lot less jovial than Trump getting in on the rights side and going full Nazi.