Former Speaker Nancy Pelosi, D-Calif., plans to endorse Jack Schlossberg, the grandson of the late President John F. Kennedy, in his run for the competitive House seat representing the 12th District of New York, a source familiar with the matter told NBC News.

Schlossberg, 33, an online political commentator and also cousin of Health and Human Services Secretary Robert F. Kennedy Jr. — of whom he has been critical — announced his candidacy in November. He is running for the seat currently held by Rep. Jerry Nadler, a Democrat, who is retiring.

The New York Times first reported Pelosi’s intent to endorse Schlossberg.

NBC News has reached out to Schlossberg’s campaign for comment.

Schlossberg will vie for the seat in a crowded Democratic primary in June. Other candidates include state Assemblymembers Micah Lasher and Alex Bores. George Conway, a conservative lawyer and Trump critic, is also running for the seat as a Democrat.

Schlossberg said in a video announcing his candidacy in November that he is “running for Congress to represent my home, New York’s 12th congressional district, where I was born and raised, where I took the bus to school every single day from one side of the district to the other.”

He’s gained a notable following on social media, with fans drawn toward his candid, freewheeling and sometimes crass political commentary style.

The 12th congressional district of New York composes the geographical heart of Manhattan, including all of Central Park.

“We have the best hospitals and schools, restaurants and museums,” Schlossberg said in his statement announcing his candidacy. “This is the financial and media capital of the world. This district should have a representative who can harness the creativity, energy and drive of this district and translate that into political power in Washington.”