They share the same enemy. Its a hate-based alliance.
My wife asks me this question all the time referring to liberals in general: “What do they think will happen to them when they get rid of all [businesses/energy production/wealth]?”
My only answer in that they always think they will be e empt. I think of the Irish gang scene in “Gangs of New York” where the mobs are breaking into rich peoples’ houses. The rich people kill a few then are overwhelmed.