In the library of James Madison High School in Brooklyn on Sunday afternoon, Senator Chuck Schumer took stock of the splash he made a few days before. In a speech on the Senate floor, he had branded Prime Minister Benjamin Netanyahu of Israel a major impediment to peace in the Middle East and called for elections to replace him when the war winds down. It was here, he recalled, inside this hulking red brick school deep in south Brooklyn, where at 16 he was glued to his transistor radio to hear breaking news of the Arab-Israeli War of 1967. It...