Congressman Charles Rangel has said his main rival is running solely on his ethnicity.
His remarks came during a debate for New York's 13th Congressional District.
If elected, State Senator Adriano Espaillat would be the first Dominican member of Congress—a point Rangel brought up several times during the debate.
"He wants to be the Jackie Robinson of the Dominicans in the Congress, which is ambitious but the fact is that Jackie Robinson was a star before he reached the major leagues and he's not a Jackie Robinson," said Rangel.
"I'm really sad that the congressman tries to frame this race among racial and ethnic silos. I think that's a disservice to your constituents, Congressman," Espaillat said.
The primary election takes place on June 24.