A Justice Department investigation into influence-peddling on Capitol Hill is focusing on a "first tier" of lawmakers and staffers, both Republicans and Democrats, say sources close to the probe that has netted guilty pleas from lobbyist Jack Abramoff. Law-enforcement authorities and others said the investigation's opening phase is scrutinizing Sens. Conrad Burns, Montana Republican; Byron L. Dorgan, North Dakota Democrat; and Minority Leader Harry Reid, Nevada Democrat, along with Reps. J.D. Hayworth, Arizona Republican, and Bob Ney, Ohio Republican. A source working with the Justice Department on the investigation told The Washington Times that Abramoff was questioned during several interviews...