The Democratic Party is becoming more and more radicalized each year. One of their candidates is an old Marxist and that Marxist got traction.
The Democratic Party used to have people like Hubert Humphrey, Daniel Patrick Moynihan(sp), Scoop Jackson, even Mondale that, although one can philosophically disagree with them, they still loved the country and knew right from wrong.
Today, it's environmental radicalism, defund the police, , identity politics, and ignore,and at times, cheer on rioters and looters