Adriano Espaillat, the Dominican-born state senator from Upper Manhattan who nearly deposed Representative Charles B. Rangel in 2012, said on Thursday that he would challenge Mr. Rangel, the 22-term Harlem Democrat, again in the primary in June.

Mr. Espaillat’s near miss two years ago, by fewer than 1,100 votes and 3 percentage points, pointed up the tectonic changes to Mr. Rangel’s district over time: from being the center of African-American political power to having a predominantly Latino constituency, with large Dominican and Puerto Rican populations as well as a significant number of white residents.

“We need a champion in Washington who will be able to bring this whole district together,” Mr. Espaillat said at a campaign kickoff in the United Palace Theater in Washington Heights — though the date chosen for the rally, supporters noted pointedly, was Dominican Independence Day.

Mr. Espaillat, 59, who is seeking to become the first Dominican-born member of the House, clearly profited from the district’s ethnic shift, crushing Mr. Rangel in their first contest in the heavily Dominican areas of Washington Heights and Inwood.