Why didn’t the AIPAC spend $15 million to buy AOCs seat as well if that’s all there is to it?

I think something you may not be taking into account is that Bowman’s district was redrawn since he first got elected, drastically changing his constituency:

The congressional district’s boundaries have shifted since Bowman first won office in 2020, losing most of its sections in the Bronx and adding more of Westchester County’s suburbs. Today, 21% of its voting-age population is Black and 42% is non-Hispanic white, according to U.S. Census figures, compared to 30% Black and 34% white in the district as it existed through 2022. Bowman is Black. Latimer is white.

This change made him particularly susceptible to a primary challenge, regardless of PAC spending.

This article shows the AIPAC has contributed almost $900 thousand to Wesley Bell’s campaign as of April 30th. This isn’t total spending in the race, just direct campaign contributions. Still less than they contributed to the Latimer’s campaign for sure, but not insignificant. We’re still almost 6 weeks until the Missouri primary election which is when the spending usually ramps up. To do an apples to apples comparison at this point in time would take more time than I care to invest but I’d love to see the results if you want to do it. Regardless of the exact figures, it’s clear the AIPAC is targeting only specific progressive Democratic candidates, and it seems to me the reason they’re doing so is because the candidates are already politically vulnerable.

Also Latimer beat Bowman by nearly 17% per NBC news.