U.S. Rep. Bobby Rush said just three weeks ago that Illinois Gov. Rod Blagojevich has "no moral basis" to appoint someone to fill Barack Obama's vacant U.S. Senate seat -- a stark contrast to his endorsement of Blagojevich's appointment on Tuesday.

Rush joined Blagojevich at his press conference in Chicago to support the pick of Roland Burris, a former state attorney general. Rush said Burris, who is black, would fill the racial void left by Obama as the only black member of the U.S. Senate. 

"This is a good decision. Roland Burris is worthy. He has not, in 40 years of public service, had one iota of taint on his record as a public servant," Rush said. 

But the Democratic congressman from Illinois expressed a different view on Dec. 9, the day Blagojevich was arrested and accused of trying to sell Obama's seat.

"His goose is cooked," Rush said of the governor. "He has no moral basis for appointing the next senator from the state of Illinois. ... That person would be as tainted as they could be." 

Rush said Blagojevich should not make an appointment, and he added that anybody he appoints would be at a "severe disadvantage" when it comes time to run for election in 2010. 

On Tuesday, Rush urged the public not to "hang and lynch" Burris simply because he was appointed by Blagojevich.