An example of "extreme right-wing, Neo-fascist diatribe" is Turmp's threats to use the executive and judicial branches of government to "go after" his legislative branch political opponents and, of course, his claim that he will be a "dictator" on day one of his presidency.
The attempt to "preserve their culture" is also an example of an extreme right-wing goal. Left-wingers, like me, are not only open to evolving their culture by welcoming immigrants but encouraging it.
I agree with you somewhat that "the left ...has lost its way," but that is because of the tremendous pressure it's being put under by Trump and his extreme-right, MAGA supporters. But it is my hope that the left will continue to have influence, like an expansion of inclusiveness and "wokeness," in our schools and universities and will continue to expand our government programs until we truly have a country who's economy is based on democratic socialism, not plutocratic capitalism.