Tainted from the day he was appointed by ousted Illinois Gov. Rod Blagojevich and resented by Senate leaders who allowed themselves to be coerced into seating him, Burris has never risen above outcast in the august 100-member chamber.
The evidence is everywhere he goes on Capitol Hill.
Colleagues, with little to say to him besides hello, beat a path around him on the Senate floor. None of the Senate's tribal customs of collegiality and acceptance - backslapping, hugging, arm-touching and collaborating on legislation - are bestowed upon Burris. The 71-year-old freshman has not been taken under a wing of a veteran senator.
Burris often can be found standing between colleagues otherwise engaged, seeing the backs of their heads.
The other senator from Illinois, Majority Whip Dick Durbin, did the senatorial equivalent of telling him to resign. Burris refused, denying all wrongdoing in a suspected pay-to-play scheme. Even so, Democrats made clear they will not support him if he runs next year for the seat that President Barack Obama won in 2004.
In the meantime, Burris joins a prestigious pantheon of the Senate's unwanted.
But even there, he doesn't exactly fit in. Burris' unsavoriness, real or perceived, doesn't rise to the level of wrongdoing that has inspired senators-past to expel 15 members or to censure nine. Their transgressions ranged from treason during wartime to abusing colleagues, sexual harassment and corruption.
"What distinguishes it is the governor who appointed him, and the cloud that the governor was under, and the implication that this appointment was done for corrupt reasons," said Ross K. Baker, author of "Friend and Foe in the U.S. Senate" and a political science professor at Rutgers University.
Burris' "colleagues would view a too-close association with him as being a kind of contamination," Baker added, "in a sense that he personally is an inoffensive guy but he's a carrier of the pathogen of Blagojevich."
There's a sense that Burris isn't long for the Senate, anyway.
The ethics committee and a state prosecutor are investigating whether he lied under oath when he did not reveal to Illinois lawmakers what an FBI tape confirmed: That he discussed raising money for Blagojevich and his desire for Obama's seat in the same conversation with the governor's brother.
Burris told The Associated Press that he wasn't asked about a conversation with the governor's brother and saw no reason to volunteer the information.
Burris' camp attributes the ill will to those in power who had hoped Blagojevich would appoint someone else.
"There is a concerted effort to destroy" his reputation, Burris' political consultant Delmarie Cobb said Monday. "Every time something comes out, you've got a senior senator questioning his integrity and reputation."
Democrats initially saw no upside to allowing Burris to be seated, citing the Constitution's requirement that each chamber of Congress determines its own membership. In the end, they allowed House members, chiefly Rep. Bobby Rush, D-Ill., to force their hand. Rush dared them to turn away a man who would be the Senate's only black member and alienate a critical Democratic constituency just as the party had delivered the nation's first black president.
Teeth were gritted; Burris was seated.
However big a headache to Democratic leaders, Burris carries both the value of his vote and the power of a threat, specifically the racist label that could be affixed to Democratic leaders who might offend him. Majority Leader Harry Reid, D-Nev., has made it clear that he appreciates Burris' vote at a time when the party is within reach of a 60-vote majority, enough to stop filibusters and control Senate business.
And Reid assigns Burris to preside over the Senate regularly, a largely ceremonial task in which parliamentarians and other aides script virtually every word uttered by the presiding officer.
But Burris hasn't served enough time to earn the goodwill that might have allowed him to rise, rebound or be tolerated in an overtly friendly manner.
Former Sen. Larry Craig, R-Idaho, served in Congress for a quarter century when he was arrested in an airport bathroom. Colleagues denounced him but permitted him to serve out his term, tolerated by people who genuinely liked him. Sen. David Vitter, R-La., is rebounding from being linked with a prostitute by appealing to the populism in his state. Earlier this year, Vitter used Senate procedure to put House Speaker Nancy Pelosi, D-Calif., on the defensive over his move to end automatic pay raises.
This spring, Burris has been trying to compile a record of legislation in hopes - possibly - of winning the seat outright next year.
If he is an outcast in the Senate, he has received warm welcomes back home. Several dozen supporters turned out last week during a tour of the state.
"We're lucky to have you here," said longtime friend Peter Fox, stepping up to shake Burris' hand.