A Boston city councilor walked back a tweet Thursday in which she had enlisted an antisemitic trope, writing in frustration over a federal court ruling: “ya’ll are letting the Zionists SHAKE YOU DOWN.” Councilor Kendra Lara, of the city’s sixth district, initially tweeted in response to an appellate court ruling that upheld an Arkansas law requiring state contractors to pledge not to boycott Israel. The appeals court said the law did not conflict with the First Amendment. Lara acknowledged that her tweet, which appeared to insinuate Jewish influence over the decision, relied on antisemitic stereotypes. She later deleted the tweet,...