U.S. Rep. Bobby Rush forcefully backed Blagojevich's decision on the basis of race, warning the public not to "lynch" Blagojevich's Senate pick, who is black.
Rush, an Illinois Democrat who also is black, for weeks had urged Blagojevich to name a black successor for Obama, who had been the only black official in the Senate before resigning his post to assume the presidency.
And on Tuesday, Rush joined Blagojevich's press conference to defend the selection of former state Attorney General Roland Burris for the job and to remind lawmakers that Burris would fill the racial void Obama left. Rush dared Senate leaders to try blocking Burris, after they issued a statement saying they would do just that.
"This is a matter of national importance," Rush said. "There are no African-Americans in the Senate, and I don't think that anyone, any U.S. senator who's sitting in the Senate right now wants to go on record to deny one African-American for being seated in the U.S. Senate. ... And so I intend to take that argument to the Congressional Black Caucus."
Long before Burris' selection became public, the 50-member Democratic caucus in the Senate called on Blagojevich to leave the appointment to others, saying that the charges against him would strip credibility from anyone he appointed.
Rush's stark rejection of the plan to deny Burris his seat stunned Senate staffers and their bosses and ignited a major internal fight among Democrats just as the party was preparing to celebrate Obama's election as the nation's first black president.
"This is not about Mr. Burris; it is about the integrity of a governor accused of attempting to sell this United States Senate seat," Majority Leader Harry Reid, D-Nev., and his deputy, Sen. Dick Durbin, D-Ill., said in a joint statement.
Rush said Tuesday he intends to take his argument first to Durbin. His statements tee off what could be a nasty fight over Blagojevich's decision.
Burris became the first black candidate elected statewide when he became the state comptroller in the late 1970s. He later served as state attorney general from 1991 to 1995.
While lawmakers avoided impugning Burris' credentials, they blasted the governor for exercising his appointment powers.
But Rush, a former Black Panther member, praised Burris as "worthy" and urged lawmakers -- as Blagojevich did -- to distinguish the governor from his nominee.
"I will ask you to not hang and lynch the appointee as you try to castigate the appointer. Separate, if you will, the appointee from the appointed," Rush said.
The last time the Senate refused to seat a member was in 1947, when Mississippi Democrat Theodore Bilbo was accused of corruption and bribery, according to Don Ritchie, associate Senate historian.
The Associated Press contributed to this report.