And these are his people. Trump’s defenders bristle at such charges, noting that Trump’s own daughter, son-in-law and some of his grandchildren are Jewish and that he is a staunch friend of Israel. He moved the embassy to Jerusalem, they say. What about the “Abraham Accords,” they say. But Trumpism (and Trump himself) has given oxygen to renascent antisemitism that has been introduced and normalized — by social media, celebrities and politicians — to a new audience that is impossible to quantify but may number in the millions. A 2020 survey by the Anti-Defamation League found that a majority of...