The Replacement.(Roland Burris)

Roland Burris still occupies temporary office space in the Dirksen Senate Office Building, in a suite far from the floor of the United States Senate, so when the buzzer signalling an imminent vote interrupted his lunch the other day, he put down his plastic soupspoon, left his sandwich untouched, and hustled out into the marble hallway. "I'm not missing any votes," he said. "They'll get on me for that, too."

Burris, the junior senator from Illinois, is trim and fit for a man of seventy-one, with a full head of hair barely flecked with gray. He beckoned a young aide to keep up as he bounded toward an elevator reserved for senators. There, Burris was joined by two Democratic colleagues, first Maria Cantwell, of Washington state, then Blanche Lincoln, of Arkansas. Burris had been a senator for less than two months--he was appointed by Rod Blagojevich, then the governor of Illinois, on December 30th, to fill the unexpired term of Barack Obama--and he had yet to learn the names of all of his colleagues. "Hello, Senator!" Burris said cheerfully to each woman. They nodded, smiled back at him, and, looking slightly embarrassed, stared down at the floor.

In the basement of the building, Burris raced to catch the subway to the Capitol, and when he arrived he met Ron Wyden, of Oregon, and Bernie Sanders, of Vermont, who, having already voted, were heading in the opposite direction. "Senators!" Burris said, and the two men made the same gestures as the pair in the elevator had: a friendly nod followed by an averted gaze. Burris darted into one of the tiny elevators that take senators up to the Senate floor, and Tom Coburn, the Oklahoma Republican, wrapped an arm around his shoulder, squeezing so hard that the men's heads were practically touching. "Hang in there, my buddy!" Coburn said.

Few senators in history have made a more ignominious national debut than Roland Burris. Blagojevich appointed Burris, a former Illinois comptroller and attorney general, just three weeks after the Governor had been arrested and taken from his home in handcuffs. Blagojevich was charged with crimes relating to his alleged attempts to exploit his office for personal and political gain, including trying to sell Obama's Senate seat. (Blagojevich maintains he did nothing wrong.) The entire Democratic caucus in the Senate, as well as the President-elect, asked Burris to refuse the appointment, and Blagojevich was impeached and removed from office a few days later. Burris ignored the entreaties, assumed the office, and plunged almost immediately into another scandal.

In a succession of raucous public appearances, Burris gave contradictory, perhaps even self-incriminating, explanations of the circumstances leading to his appointment. (He has both denied and admitted discussing the Senate seat with Blagojevich's advisers in advance of his selection.) In short order, editorials in the Chicago Tribune and Sun-Times called for Burris's resignation, a demand echoed by the new governor of Illinois, Pat Quinn, and by Dick Durbin, the state's senior senator. "As far as my colleagues here in the Senate, they are grasping as I am to try to get to the truth of this situation," Durbin said after failing to persuade Burris to quit. "They are confused and concerned about the disclosures that have been made." An Illinois prosecutor is investigating Burris for possible perjury and related crimes, and the matter is also before the Senate Ethics Committee.

During his long career in Illinois politics, Burris has encountered many of the state's most influential figures, some of them principled risk-takers and some corrupt rogues. And it's been clear that Burris belongs to neither category. He is a conventional politician, one guided far more by cautious self-interest than by ideological passion. His self-regard may be greater than that of some of his peers; he is especially known for the words of self-celebration carved into the wall of a mausoleum that is waiting for him in a Chicago cemetery. (The structure bears the inscription "Trail Blazer" and lists such accomplishments as being the first African-American undergraduate at Southern Illinois University to be an exchange student at the University of Hamburg, in Germany.) "He was a figure of fun, because he was highly egocentric," Alan Dobry, a former Democratic ward committeeman in Chicago, said of Burris's years as a local politician. "When he was in office, he had two aides who went around with him, and they were generally referred to as the 'Rolaids.' " According to the Harvard sociologist William Julius Wilson, a longtime student of Chicago politics, Burris "was a soldier, part of the machine. He's not a distinguished politician. He's not a powerful political thinker." Of course, this description hardly distinguishes Burris from many of his colleagues on Capitol Hill. In his very ordinariness, Burris may represent a triumph of sorts for the civil-rights movement, which was, at least in part, a struggle for black people to be seen as just like everybody else.

Roland Burris's paternal grandfather was born in Tennessee, but around the turn of the last century he moved to Centralia, a small city two hundred and seventy miles south of Chicago, in the heartland of Illinois. Even ...