The word “cuck” is short for “cuckold,” and up until recently was used most often to describe a subgenre of pornography in which a hapless husband is forced to not only watch his wife have sex with another man but — oh dear, I had better stop. In any event, its adoption as a political term — meaning a conservative of insufficient, er, conviction — is just one of the many ways American discourse was enhanced by the 2016 presidential campaign.

Ronnie, the protagonist of “Cuck,” directed by Rob Lambert, is an extreme sad sack entranced by right-wing internet videos and in thrall to his own bigotry. He lives with, and steals from, his ailing mother. (As with “Joker,” released on the same day , “Cuck” believes that the worst humiliation a white male can endure is having to help his female parent bathe.)

Played by Zachary Ray Sherman, Ronnie has a touch of Travis Bickle. But even the “Taxi Driver” character could get through a coffee date with a woman without assaulting her. Eventually Ronnie develops a fixation on another woman who makes porn videos. Soon he is inveigled into participating in her home productions, taking the role of, yep, the cuck.