The contest features a collision of two ambitious politicians labeled for years as rising stars in New York: Mr. Torres, a 32-year-old who became the first openly gay elected official in the Bronx and the youngest member of the City Council in 2014, and Mr. Blake, 37, a veteran of the Obama administration.
The political arm of the Congressional Hispanic Caucus is backing Mr. Torres, who is both black and Puerto Rican, while the Congressional Black Caucus is behind Mr. Blake.
“On a daily basis, I am being told a black person shouldn’t be running here,” said Mr. Blake, who also has the backing of Tom Perez, the first Latino D.N.C. chairman, who offered a rare personal endorsement.
The primary was the first contested New York congressional race in which Representative Alexandria Ocasio-Cortez made an endorsement: She is supporting Samelys López, an insurgent candidate with the backing of the Democratic Socialists of America and the Working Families Party.
The district, which neighbors Ms. Ocasio-Cortez’s seat, will be a test both of how wide her sphere of influence is and how her brand of far-left progressivism plays in an area that ranks as among the poorest and the least white in the country. Ms. Ocasio-Cortez declined an interview request.
“If you go to a black church in the South Bronx, you are unlikely to come across an assemblage of Democratic Socialist revolutionaries,” said Mr. Torres, who labels himself a pragmatic progressive. “It’s a fact that the D.S.A. has the most robust membership in wealthier, whiter gentrified neighborhoods.”
Ms. López cast herself as a “grass-roots progressive offering a radical transformative vision.” With the Bronx ravaged by the coronavirus pandemic, all the candidates have been forced to mostly campaign from home, which, for Ms. López, is across the street from the Bronx Lebanon Hospital Center. “All I hear is sirens all day,” she said.