Rubbish JGW. You have some kind of candy colored idea of what politics is that has no relationship to reality or historical record.
Now you want to run around yelling 'Extremist!' with anything that doesn't conform to your simplistic view.
By your political definition MLK and Senator Byrd were both 'left'.
Or todays Joe Manchin and Alexander Cortez are both 'Left'.

The idea of making common cause with the Left is more unpalatable to you than making concessions to the increasingly extreme right.
For what end? You and your political stripe, punching left while kissing right, have done this for decades now and is a major reason for where we are today.
Keep digging, there's gotta be a horse under all that horsesh!t somewhere.