Jack Schlossberg leads a new poll of the Democratic primary for the congressional race in New York ’s 12th District, released on Friday. Schlossberg, the grandson of former President John F. Kennedy , is viewed as a rising star in the Democratic Party. He is seeking the open race being vacated by retiring Democratic Representative Jerry Nadler in Manhattan, a solidly Democratic seat. Several other well-known Democrats are running in a competitive primary alongside Schlossberg. The Hart Research