Blagojevich has been charged with trying to sell President-elect Barack Obama's empty Senate seat for personal gain, among other things. Despite the charge, the governor Tuesday tapped former state Attorney General Roland Burris to fill the seat. Democratic leaders have suggested they may block the appointment and Obama has said Burris should not take the seat.
But a 1969 Supreme Court ruling, in a case involving the late Rep. Adam Clayton Powell Jr., D-N.Y., said Congress can bar the seating of a member only if that member fails to meet "the standing qualifications expressly prescribed by the Constitution" -- principally age, citizenship and residency and the laws of a particular state.
Congressional leaders had tried to exclude Powell for misappropriating funds and making payments to his wife.
The lower courts had supported Powell's expulsion, but the majority opinion by Chief Justice Earl Warren said the high court's "examination of relevant historical materials shows at most that Congress' power under (Article 1, section 5 of the Constitution) to judge the 'qualifications of its members' is a 'textually demonstrable constitutional commitment' ... to judge only standing qualifications which are expressly set forth in the Constitution; hence, the House has no power to exclude a member-elect who meets the Constitution's membership requirements."
Though it severely limited Congress' power to block the seating of a member, the opinion left open the question of a state taking action.