AOC comes to mind . . . somone blatantly not sane or competent who's obviously being groomed to one day become a Dem Party president of the United States of America.
The thing about the Left is that it's a question of identifiers. The radicals inside the Dem Party is no longer fringe in regards to power or influence. They are rapidly becoming the leadership and so as long as Dem Party voters swallow whole and unexamined what the Dem Party loyalist mainstream media presents to them as 'reality' this increasingly radical leadership doesn't need heaps more radicals among the rank and file voters.
History agrees with this assessment of reality. It's how the Soviet Union, Communist China, and NAZI Germany -- for that matter - came to be what . . . they came to be.