Yes, Julius Genachowski is a Jew.
Barack Obama named Genachowski as Head of the Federal Communications Commission in 2009. He announced his intention to resign in March, 2013.
Several news reports confirmed that, "Mr. Genachowski, attended yeshiva through high school and studied in yeshiva in Israel before going to Columbia... His parents are immigrants who survived the Holocaust."
Calling him a "Talmud Ace," The Forward reported:
Julius Genachowski was born August 19, 1962, to Adele and Azriel Genachowski. He grew up in Great Neck, a Long Island suburb, in a family that attended the local Young Israel. He attended Orthodox day school at North Shore Hebrew Academy and summered at Camp Raleigh. His high school was the Marsha Stern Talmudical Academy, which is part of Yeshiva University. Though he says he cut classes to play basketball, he won the Talmud award.He is the cousin of Rabbi Menachem Genack (we assume shortened from Genachowski), rabbinic administrator and CEO of O.U. Kosher, an Orthodox rabbi with liberal political views.
Genachowski spent a year after high school studying in Jerusalem at Yeshivat HaKotel, where he and his peers practiced “learning, discussing, questioning each other, even the possibilities of different points of view,” he recalled. “One of the things that you take away from learning Talmud, learning Gemara, is that two or three brilliant people can look at the same passage and have different interpretations and views, each of which makes a lot of sense, but they’re not all consistent. So I enjoyed that.”
Today, Genachowski attends Sabbath services regularly at Adas Israel, Washington’s largest Conservative synagogue.