“I consider myself an American  I was born and raised here,” he said in an interview on the porch of his home in the wooded suburb of Wallingford. “I love my people. I love my culture. I love our rice and beans, our salsa music, our language  everything my parents raised us with. But I am so grateful for the opportunity only the United States can give.”

He grew up in the troubled Fair Haven neighborhood of New Haven, a complicated city known for Yale University but also for urban decay, high crime rates and failed prospects, roots he sees as similar to Judge Sotomayor’s in a Bronx public housing project.

His father was a factory worker, and his mother took care of the couple’s three children. (In addition to his brother, David, who did not respond to interview requests, he has a sister who now lives in Puerto Rico.) The family spoke Spanish at home, making his adjustment to school “traumatic,” he said.

Lieutenant Vargas decided to follow the path of an older friend, John Marquez, whom he looked up to. Mr. Marquez had worked his way out of the neighborhood by joining the Fire Department.

“I used to tell him, ‘You know where I came from  if I can make it, anyone can,’ ” Mr. Marquez, now a deputy chief in the department, said in an interview. “ ‘But don’t expect anything to be handed to you. Work for it.’ ”

But Lieutenant Vargas’s aspirations were stymied by a 1988 lawsuit, filed by black firefighters, that shut down hiring for years. The lawsuit challenged a written test that relatively few nonwhites passed. In 1994, the city agreed to disregard the test, over union complaints, and hire 40 firefighters  20 white, 10 black and 10 Hispanic, according to The New Haven Register.