One robin does not spring make, but its chirp is still welcome. Congressman Jamaal Bowman’s thrashing in New York’s 16th District Democratic primary could be just such an augury. He lost to a moderate, George Latimer. The Times blames in part what it calls “a record shattering campaign from pro-Israel groups.” Mr. Bowman, though, hardly needed help in losing. By race’s end, he appeared more interested in leftist grandstanding than winning.

Mr. Bowman’s defeat removes from Congress one of the most baleful lawmakers on Capitol Hill. He is the first member of the so-called “Squad” to be defeated at the ballot box. He lost by double digits despite, on the campaign’s final day, the support of Senator Sanders and Representative Alexandra Ocasio-Cortez. Mr. Bowman accused Israel of apartheid and genocide and suggested that reports of sexual assault on October 7 were “propaganda.”

The onetime middle school principal walked back that claim, but his body of work proved repellent to the suburban New York district that elected to throw him out. Let it serve as a reminder to President Biden and his camarilla that catering to the left carries its risks. Some of those who hope to secure a second term for the president fret about his decaying support among Muslim voters. It turns out that Jews vote, too.

Mr. Bowman’s departure, though, leaves intact an ascendent wing of the Democratic Party implacably opposed to Israel. August presents an opportunity to further winnow that faction. Congresswoman Cori Bush, another member of the Squad, is facing a challenge in Missouri’s 1st District from St. Louis County prosecuting attorney Wesley Bell. A poll released Wednesday detects a dead heat. Mr. Bell was down double digits in January.

Axios reports a shocking development — that the House minority leader, Hakeem Jeffries, is set to come out for Ms. Bush as part of a larger strategy of, supposedly, backing incumbents. Mr. Jeffries supported Mr. Bowman, albeit without enthusiasm, under the same theory. Such a strategy could be short sighted. A party that sends the likes of Mr. Bowman and Ms. Bush to Congress is less likely to convince voters of its seriousness come November. 

Whether Mr. Bowman’s defeat is a course correction or a harbinger of further electoral trouble depends on whether the lesson of his loss is learned by a party that has refused for way too long to confront anti-Israel sentiment. Even those voters not eager to cast for President Trump could be pushed rightward by sights of leftist chaos on streets and campuses. Mr. Bowman’s ouster is both addition by subtraction and a warning.

The outcome in NY-16 comes as polling suggests that it is  conceivable that Mr. Trump could beat Mr Biden in New York. A Siena poll this week puts the 45th president a mere eight points behind the 46th. Mr. Trump’s rise, the survey discloses, is being fueled by his gains among Black and Jewish voters, usual Democratic stalwarts. The last Republican to win the Empire State was President Reagan. Could an epic upset be in the offing?