Celebrity fitness trainer Jillian Michaels pushed back Monday after New York Times contributor Wajahat Ali accused her of being a “white nationalist.” At least 15 people were killed Sunday when two assailants opened fire during a Hanukkah celebration at Sydney’s Bondi Beach, where hundreds gathered for an event known as Chanukah by the Sea, according to officials and media reports. During a discussion on “Piers Morgan Uncensored,” Ali criticized…