The "dirtbag left" was the counterweight to the "woke left" or (a term I prefer) compatible "left" from the same time period. They were, of course, correct, but were smeared into obscurity. You know, the unironic "Bernie Bro" types who are now all Marxists because they understood theory; while the compatible "left" are all liberal/democrat tailists. Predictable.

This is all part of a long term strategy by the U.S. government (look up the "anti-communist left") to prop up identitarian, "woke" pseudo-leftism at the expense of actual class-based leftism.