Missouri's Junior Senator becomes the first top statewide official to officially call for the Illinois Governor's resignation.
"Having read the transcript of Governor Blagojevich’s conversations I only have one word – prison," said Sen. Claire McCaskill in a statement.
McCaskill joined a letter, signed by all Democratic members of the Senate, that says that should Gov. Rod Blagojevich refuse to resign and appoint someone to fill Obama’s position, Congress would exercise their constitutional right to refuse to seat the Senate appointee.
"We write to insist that you step down as Governor of Illinois and under no circumstance make an appointment to fill the vacant Illinois Senate seat. In light of your arrest yesterday on alleged federal corruption charges related to that Senate seat, any appointment by you would raise serious questions," reads the letter.