I regularly get canned for not being far left enough actually. Despite being further left than easily 95% of people.
There's the crux of the problem.
Who defines 'left'?
I know for certain in US (who are mostly politically illiterate and use wrong terminology) the slightly less right wing Dem party for a great deal sees themselves as left or progressive.
Which they certainly aren't .

You have the same phenomenon in EU where in many countries you have a socialist party, that is in no way socialist.
As an example the worst being the Labour party.
They follow the same center right route as most 'acceptable' parties. usually Liberal/Conservative that keep the status quo of more and more austerity, chipping away at social policy.
The "socialists" up tp a certain part get away with it by now and then throwing a bone to the public and shamelessly put on a show on the 1 may and scream the internationale.
Where they do what politicians do, lie and pretend to be the party for the people.
When things get worse, and there is nothing more to squeeze the commoners get angry and want to be heard.
Unfortunately mostly by voting extreme right. Others to what is called 'extreme left' the actual real socialists (evil commies, tankies!) who the status quo parties demonise even more than extreme right.
After all they are the real enemy, while fascism is simply ultracapitalism and is less of a problem and when necessary even will be embraced by the traditional parties.