WASHINGTON --The head of a Republican environmental advocacy group is set to plead guilty in the Jack Abramoff scandal and is cooperating with an FBI investigation into corruption involving Congress and the Bush administration, two people close to the case said Wednesday. Italia Federici served as a go-between for Abramoff, the once-powerful lobbyist, and J. Steven Griles, the deputy interior secretary during President Bush's first term, prosecutors said Wednesday in documents charging her with tax evasion and obstructing a Senate inquiry into the Abramoff scandal. Under a deal with the Justice Department, she must cooperate with authorities and is identifying...