Trump has lost the election in the end - the market place of ideas has worked. Establishment prevented the coup -- representative democracy has worked. No need to change anything. Maybe force the 1st amendment on the big tech when an account is verified as non-anonymous.

Also the so called "existential threat" is the result of serious internal issues in the country. (changing demographics, the deindustrialization by the international capital with a tacit agreement of the establishment, the chasm between values of the educated class and the rest of the country)