As he runs for mayor of New York City, Zohran Mamdani has made his identity as a Muslim immigrant of South Asian descent a key part of his appeal.
But as a high school senior in 2009, Mr. Mamdani, the Democratic nominee, claimed another label when he applied to Columbia University. Asked to identify his race, he checked a box that he was “Asian” but also “Black or African American,” according to internal data derived from a hack of Columbia University that was shared with The New York Times.

Columbia, like many elite universities, used a race-conscious affirmative action admissions program at the time. Reporting that his race was Black or African American in addition to Asian could have given an advantage to Mr. Mamdani, who was born in Uganda and spent his earliest years there.