Freedom House

https://freedomhouse.org/report/freedom-world/2021/democracy-under-siege

USA leaves realm of France and UK, goes down to the ranks of countries like Panama and Romania:

Good overview of the situation - https://thebulwark.com/trump-is-gone-but-american-democracy-is-still-in-danger/

The Freedom House report is worth reading for the details of the mechanisms of racism, political polarization, and money in politics. The USA is compared here to countries that are marked as less free or not free. Only Italy in the developed world is worse than the USA in 'money in politics' category.