There were three left wing political purges in this country. (O.K. you could argue four).
The 20's, 50's and 70's.
There are no left wing political parties in the U.S. Of any account anyway.
there are only two right wing ones. One of them is O.K. with homosexuality and somewhat with race. Economically, there's not a great deal of difference, symbolized with the candidate the Democratic party/media is backing and the one it's kneecappings.
Unless your working off of another 'Left' template of identity politics while ignoring economics and class, I have seen no leftist progress, only regression economically and politically, IMO.
As far as going left I see no chance of that with political and media obstacles and no Leftists political parties large enough to take advantage of opportunities like there were in the 30's. AFL-CIO is a paid off shell, no Anarchists, socialist or communist parties as there are in other countries. I see fascism in our near future as a left wing option has been denied by the liberal party leaders.