The rot in USA Politics is what is going to destroy democracy and the problem is with the leftists and socialists who want to destroy the US Constitution and replace it with a socialist dictatorship. That is a rather sweeping statement and it did not start with Trump at all.
Obama started the rot by allowing his Democratic Party to become totally corrupt and his administration was the most corrupt in the history of the USA, The problem was that he captured the FBI and Security Services to prevent investigation of the looting spree and the same time used then to create scandals against people that caused problems for him and his psrty. So how did the looting work? Biden's and Pelosi's sons were used in Ukraine and US Aid money was used for looting purposes. the money was allocated to corrupt companies and vanished. There were extensive usage of the Clinton Foundation to fund corruption - eg in the Uranium I case - and the company of Biden's sun was used to buy out the shares in a armaments company - with secret plans then leaked to China and then a huge commission paid. In fact what happened was high treason - and was followed up belatedly by the FBI recently.
What is happening now is equally treasonous - the Democrats work with the Chinese and Soros to cause demonstrations about racism That soon turn to riots, looting, arson and murder - the estimated damage to private and state property amounted to billions of dollars, The main function of the protestors are to intimidate people into submission. The media in general - also CNN partly owned by the Chinese - tried to call the demonstrations peaceful, but the fact is it was not and the Democrat leadership protect the rioting criminals in the States and cities run by their party.
The other problem is that the leftists in the Democratic Party realizes that their intended policies would be unacceptable to the voters so they put up the utterly corrupt Biden as their candidate for President. They know enough about the Biden corruption as well and he will just be a puppet for the extreme leftists. He showed signs of age dement6ia anyway. They will ensure that the USA is turned into a Third World Country with corrupt leadership and virtually no middle class, .