Fining Donald Trump $1,000 per gag order violation is a joke, key trial witness Michael Cohen and former prosecutor Glenn Kirschner agreed on Cohen’s”Mea Culpa” podcast, which aired Friday. Prosecutors have proposed the punishment if a judge finds Trump broke the order with social media posts aimed at witnesses — including Cohen. Judge Juan Merchan has scheduled a Tuesday hearing after Manhattan District Attorney Alvin Bragg accused Trump of contempt for what he said were multiple violations. Kirschner was furious to see the court try to hold out for so long. “You don’t let somebody violate co…