Glenn Poshard, the 1998 Democratic nominee for governor, is weighing a possible bid for the U.S. Senate. Poshard, 57, who has just stepped down as vice chancellor for administration at Southern Illinois University, has been encouraged by political allies to make a run for the seat that is being vacated by Republican Peter G. Fitzgerald. His populist message and dynamic campaign style would add excitement to the Democratic primary. At least six other Democrats are already in the field. Poshard has encouraged state Comptroller Dan Hynes to make the race and many of his former allies including Cook County Commissioner...