The Anti-Defamation League's Center on Extremism released a substantially updated version of its backgrounder on the Democratic Socialists of America on Wednesday, adding material from the past two years and highlighting New York City Mayor Zohran Mamdani as an example of an elected official advancing an anti-Israel agenda."The previous update to that backgrounder was in September 2024," an ADL spokesperson told JNS. "Anything that happened betw…