A war over Israel has erupted between famously liberal Upper West Side moms — and even more left-wing mommies. Morgan Roslyn Cohn, 26, claims she and her husband were booted from the Upper West Side Moms Facebook group last month because she posted on her profile picture, “Stand with Israel.” The fallout caused a firestorm, with Cohn charging antisemitism and other members demanding an explanation for the expulsion. An administrator claimed Cohn was bullying others on the site. “The administrator was very upset that I was calling her out for being antisemitic,” Cohn, a teacher, told The Post. “I would...