Political operative David Brock helped lead the smear campaign against Clarence Thomas’ sexual harassment accuser Anita Hill — and he said he’s still doing penance for what he calls his “original sin.” Brock was a young conservative when he sneered that Hill was “a bit nutty and a bit slutty” in an infamous report based on dubious sourcing. But three decades later he’s publishing “Stench: The Making of the Thomas Court and the Unmaking of America” to denounce the right-wing transformation of the judicial branch, reported the New York Times. “The real interest of Brock’s book lies in his singul…