I'm not aware of any tangible evidence of Marcus being gay. Just the gaydar alarms for half the gay men in North America going off all at once.
You sure it's not just "wishful thinking" on your part? He does have that sort of Ernest Borgnine thing going on
He might, since Ernest Borgnine is an extreme right-winger. Whom I actually admire on a certain level, given his WWII service, and the wonderful things he's done as an actor. Despite my reputation here, I can separate the man from his politics, if I find it justified.
But Marcus has no redeeming features of which I'm aware, not a heroic military veteran, not an Academy Award-winning actor. He grabs government money to turn gays into straights, claiming it's a choice that can be reversed. I don't see the connection with Borgnine.