While there certainly is a purity issue, I see those leftist perfectionists as covert conservatives. They very disproportionately come from GOP families & communities. The same is true of the far more numerous "moderate"(i.e. conservative) Democrats. Moderates far outnumber purists.
I couldn't tell you which political party my working-class parents were affiliated with. It never came up. Maybe that's one of the reasons why I'm not strongly affiliated with any particular political party or movement. I'm more concerned with actual beliefs than political labels.
My parents were liberal Democrats. It came up a lot. I'm very concerned with those labels. They're quite meaningful.
I'm more concerned with peoples' actions and actual attitudes.
Actions and attitudes are quite correlated with the labels. For example, GOP voters elect nearly 100% mediocre, ignorant, racist, sexist white leaders, over 90% of whom are white men. They are ending democracy entirely.
They are. We've lost the republic.