Steven Gilliard Jr., a political journalist who found his calling as a combative and influential blogger on the left, died on Saturday in Manhattan. He was 42.

He died after having been hospitalized at Lenox Hill Hospital since February because of heart and kidney failure, said his cousin Francine Smith, a spokeswoman for the family.

From his perch at The News Blog, whose advertisements and donations paid for his modest living expenses, Mr. Gilliard offered his powerful readership a blunt and passionate take on the events of the day. He was one of fewer than a dozen liberal political bloggers to make a living from his blog, said Markos Moulitsas Zúniga, the founder of the Daily Kos Web site, to which Mr. Gilliard had been an early contributor.

Mr. Gilliard was born in Harlem and attended Hunter College Elementary School and Hunter College High School before graduating with a degree in journalism from New York University.