The Democrats have an anti-Semitism problem, and it isn’t subtle. Minnesota Rep. Ilhan Omar tweeted Sunday that congressional support for Israel is “all about the Benjamins baby,” a slang term for $100 bills—a straightforward accusation that American lawmakers who support the Jewish state are being bought off. Who does she think is paying American politicians to be pro-Israel, the Forward’s opinion editor asked. “AIPAC!” Ms. Omar gleefully replied, notwithstanding that the American Israel Public Affairs Committee does not contribute to political campaigns.

House Democratic leaders—though none of the Democrats running for president—quickly condemned Ms. Omar’s smear, saying in a statement that her “use of anti-Semitic tropes and prejudicial accusations about Israel’s supporters” was “hurtful” and “deeply offensive.” Senate Minority Leader Chuck Schumer said her “anti-Semitic stereotype” was “offensive and irresponsible.”

All true, but beside the point.

That Ms. Omar would slander Israel is disturbing not because of the feelings it tramples. Since her appointment to the House Foreign Affairs Committee, her statement raises alarm about how her enmity for the world’s only Jewish country—and the world’s largest Jewish population—might translate into policy aims. The issues for Israel’s supporters are security and survival, not hurt feelings, which are trivial in comparison. Assuming that all Jews love gefilte fish, play klezmer music, and suffer overbearing mothers? Those are stereotypes. Actively working to isolate Israel and accusing pro-Israel Jews of bribing Congress isn’t “insensitive.” It’s something far darker and more malevolent.

Talk of “tropes” and “stereotypes” betrays the left’s understanding of prejudice, which recognizes no distinction between threats and thoughts. Ms. Omar’s statements require no sophisticated parsing, nor a deep understanding of historical prejudice; real hatred rarely does. Hers is repeated, focused, overt and jubilant. It is bookended with musical notes, as her “all about the Benjamins” tweet was; it ends in an exclamation mark or is stamped with an arm-flex emoji, as was her “apology,” which ran under the defiant heading “Listening and learning, but standing strong,” and read in part: “I unequivocally apologize. At the same time . . .”