After four years in office, FCC chairman Julius Genachowski is stepping down today. Genachowski pioneered an ambitious plan for rural broadband and a shift toward net neutrality, but his leadership was also seen by some as plodding and ineffective. Regardless, in a candid interview with The New Yorker, Genachowski says he remains an optimist, though he acknowledges the limits of how far he was able to change national policy during his tenure. He also touches on some of the most controversial decisions made under his leadership, from rejecting an AT&T / T-Mobile merger but approving an NBC / Comcast one to absolving Red Sox player David Ortiz for using profanity on the air during a memorial speech after the Boston Marathon bombings. After his departure, meanwhile, telecom industry veteran Tom Wheeler will step up to fill Genachowski's shoes at the FCC.