At least some of them were viewed as a threat. The Socialist Workers Party was relentlessly harassed and infiltrated by the FBI. At one point a third of their members were paid informants. Prominent members and leaders got yearly investigations where the FBI went to their bosses and landlords to question them about their “subversive activities”. This is all despite their incredibly tame platform of entryism and rarely supporting AES countries.
It’s all documented in a lawsuit they won against the US government: https://law.justia.com/cases/federal/district-courts/FSupp/642/1357/2398821/
Did not know that. Won’t be resubscribing