By JODI KANTOR

CHICAGO — The young law professor stood apart in too many ways to count. At a school where economic analysis was all the rage, he taught rights, race and gender. Other faculty members dreamed of tenured positions; he turned them down. While most colleagues published by the pound, he never completed a single work of legal scholarship.

At a formal institution, Barack Obama was a loose presence, joking with students about their romantic prospects, using first names, referring to case law one moment and “The Godfather” the next. He was also an enigmatic one, often leaving fellow faculty members guessing about his precise views.

Mr. Obama, now the junior senator from Illinois and the presumptive Democratic presidential nominee, spent 12 years at the University of Chicago Law School. Most aspiring politicians do not dwell in the halls of academia, and few promising young legal thinkers toil in state legislatures. Mr. Obama planted a foot in each, splitting his weeks between an elite law school and the far less rarefied atmosphere of the Illinois Senate.

Before he outraised every other presidential primary candidate in American history, Mr. Obama marched students through the thickets of campaign finance law. Before he helped redraw his own State Senate district, making it whiter and wealthier, he taught districting as a racially fraught study in how power is secured. And before he posed what may be the ultimate test of racial equality — whether Americans will elect a black president — he led students through African-Americans’ long fight for equal status.

Standing in his favorite classroom in the austere main building, sharp-witted students looming above him, Mr. Obama refined his public speaking style, his debating abilities, his beliefs.

“He tested his ideas in classrooms,” said Dennis Hutchinson, a colleague. Every seminar hour brought a new round of, “Is affirmative action justified? Under what circumstances?” as Mr. Hutchinson put it.

But Mr. Obama’s years at the law school are also another chapter — see United States Senate, c. 2006 — in which he seemed as intently focused on his own political rise as on the institution itself. Mr. Obama, who declined to be interviewed for this article, was well liked at the law school, yet he was always slightly apart from it, leaving some colleagues feeling a little cheated that he did not fully engage. The Chicago faculty is more rightward-leaning than that of other top law schools, but if teaching alongside some of the most formidable conservative minds in the country had any impact on Mr. Obama, no one can quite point to it.

“I don’t think anything that went on in these chambers affected him,” said Richard Epstein, a libertarian colleague who says he longed for Mr. Obama to venture beyond his ideological and topical comfort zones. “His entire life, as best I can tell, is one in which he’s always been a thoughtful listener and questioner, but he’s never stepped up to the plate and taken full swings.”

Mr. Obama had other business on his mind, embarking on five political races during his 12 years at the school. Teaching gave him satisfaction, along with a perch and a paycheck, but he was impatient with academic debates over “whether to drop a footnote or not drop a footnote,” said Abner J. Mikva, a mentor whose own career has spanned Congress, the federal bench and the same law school.

Douglas Baird, another colleague, remembers once asking Mr. Obama to assess potential candidates for governor.

“First of all, I’m not running for governor, “ Mr. Obama told him. “But if I did, I would expect you to support me.”

He was a third-year state senator at the time.

Popular and Enigmatic

Mr. Obama arrived at the law school in 1991 thanks to Michael W. McConnell, a conservative scholar who is now a federal appellate judge. As president of The Harvard Law Review, Mr. Obama had impressed Mr. McConnell with editing suggestions on an article; on little more than that, the law school gave him a fellowship, which amounted to an office and a computer, which he used to write his memoir, “Dreams From My Father.”

The school had almost no black faculty members, a special embarrassment given its location on the South Side. Its sleek halls bordered a neighborhood crumbling with poverty and neglect. In his 2000 Congressional primary race, Representative Bobby L. Rush, a former Black Panther running for re-election, used Mr. Obama’s ties to the school to label him an egghead and an elitist.

At the school, Mr. Obama taught three courses, ascending to senior lecturer, a title otherwise carried only by a few federal judges. His most traditional course was in the due process and equal protection areas of constitutional law. His voting rights class traced the evolution of election law, from the disenfranchisement of blacks to contemporary debates over districting and campaign finance. Mr. Obama was so interested in the subject that he helped Richard Pildes, a professor at New York University, develop a leading casebook in the field.

His most original course, a historical and political seminar as much as a legal one, was on racism and law. Mr. Obama improvised his own textbook, including classic cases like Brown v. Board of Education, and essays by Frederick Douglass, W. E. B. Dubois, the Rev. Dr. Martin Luther King Jr. and Malcolm X, as well as conservative thinkers like Robert H. Bork.

Mr. Obama was especially eager for his charges to understand the horrors of the past, students say. He assigned a 1919 catalog of lynching victims, including some who were first raped or stripped of their ears and fingers, others who were pregnant or lynched with their children, and some whose charred bodies were sold off, bone fragment by bone fragment, to gawkers.

“Are there legal remedies that alleviate not just existing racism, but racism from the past?” Adam Gross, now a public interest lawyer in Chicago, wrote in his class notes in April 1994.

For all the weighty material, Mr. Obama had a disarming touch. He did not belittle students; instead he drew them out, restating and polishing halting answers, students recall. In one class on race, he imitated the way clueless white people talked. “Why are your friends at the housing projects shooting each other?” he asked in a mock-innocent voice.

A favorite theme, said Salil Mehra, now a law professor at Temple University, were the values and cultural touchstones that Americans share. Mr. Obama’s case in point: his wife, Michelle, a black woman, loved “The Brady Bunch” so much that she could identify every episode by its opening shots.

As his reputation for frank, exciting discussion spread, enrollment in his classes swelled. Most scores on his teaching evaluations were positive to superlative. Some students started referring to themselves as his groupies. (Mr. Obama, in turn, could play the star. In what even some fans saw as self-absorption, Mr. Obama’s hypothetical cases occasionally featured himself. “Take Barack Obama, there’s a good-looking guy,” he would introduce a twisty legal case.)

Challenging Assumptions

Liberals flocked to his classes, seeking refuge. After all, the professor was a progressive politician who backed child care subsidies and laws against racial profiling, and in a 1996 interview with the school newspaper sounded skeptical of President Bill Clinton’s efforts to reach across the aisle.

“On the national level, bipartisanship usually means Democrats ignore the needs of the poor and abandon the idea that government can play a role in issues of poverty, race discrimination, sex discrimination or environmental protection,” Mr. Obama said.

But the liberal students did not necessarily find reassurance. “For people who thought they were getting a doctrinal, rah-rah experience, it wasn’t that kind of class,” said D. Daniel Sokol, a former student who now teaches law at the University of Florida at Gainesville.

For one thing, Mr. Obama’s courses chronicled the failure of liberal policies and court-led efforts at social change: the Reconstruction-era amendments that were rendered meaningless by a century of resistance, the way the triumph of Brown gave way to fights over busing, the voting rights laws that crowded blacks into as few districts as possible. He was wary of noble theories, students say; instead, they call Mr. Obama a contextualist, willing to look past legal niceties to get results.

For another, Mr. Obama liked to provoke. He wanted his charges to try arguing that life was better under segregation, that black people were better athletes than white ones.

“I remember thinking, ‘You’re offending my liberal instincts,’ ” Mary Ellen Callahan, now a privacy lawyer in Washington, recalled.

In his voting rights course, Mr. Obama taught Lani Guinier’s proposals for structuring elections differently to increase minority representation. Opponents attacked those suggestions when Ms. Guinier was nominated as assistant attorney general for civil rights in 1993, costing her the post.

“I think he thought they were good and worth trying,” said David Franklin, who now teaches law at DePaul University in Chicago.

But whether out of professorial reserve or budding political caution, Mr. Obama would not say so directly. “He surfaced all the competing points of view on Guinier’s proposals with total neutrality and equanimity,” Mr. Franklin said. “He just let the class debate the merits of them back and forth.”

While students appreciated Mr. Obama’s evenhandedness, colleagues sometimes wanted him to take a stand. When two fellow faculty members asked him to support a controversial antigang measure, allowing the Chicago police to disperse and eventually arrest loiterers who had no clear reason to gather, Mr. Obama discussed the issue with unusual thoughtfulness, they say, but gave little sign of who should prevail — the American Civil Liberties Union, which opposed the measure, or the community groups that supported it out of concern about crime.

“He just observed it with a kind of interest,” said Daniel Kahan, now a professor at Yale.

Nor could his views be gleaned from scholarship; Mr. Obama has never published any. He was too busy, but also, Mr. Epstein believes, he was unwilling to put his name to anything that could haunt him politically, as Ms. Guinier’s writings had hurt her. “He figured out, you lay low,” Mr. Epstein said.

The Chicago law faculty is full of intellectually fiery friendships that burn across ideological lines. Three times a week, professors do combat over lunch at a special round table in the university’s faculty club, and they share and defend their research in workshop discussions. Mr. Obama rarely attended, even when he was in town.

“I’m not sure he was close to anyone,” Mr. Hutchinson said, except for a few liberal constitutional law professors, like Cass Sunstein, now an occasional adviser to his campaign. Mr. Obama was working two other jobs, after all, in the State Senate and at a civil rights law firm.

Several colleagues say Mr. Obama was surely influenced by the ideas swirling around the law school campus: the prevailing market-friendliness, or economic analysis of the impact of laws. But none could say how. “I’m not sure we changed him,” Mr. Baird said.

Because he never fully engaged, Mr. Obama “doesn’t have the slightest sense of where folks like me are coming from,” Mr. Epstein said. “He was a successful teacher and an absentee tenant on the other issues.”

Leaving the Classroom

As Mr. Obama built his political career, his so-called groupies became an early core of supporters, handing out leaflets and hosting fund-raisers in their modest apartments.

“Maybe we charged an audacious $20?” said Jesse Ruiz, now a corporate lawyer in Chicago. Mr. Obama was sheepish asking for even that, Mr. Ruiz recalls. With no staff, Mr. Obama would come by the day after a fund-raiser to stuff the proceeds into a backpack.

Mr. Obama never mentioned his humiliating, hopeless campaign against Mr. Rush in class (he lost by a two-to-one margin), though colleagues noticed that he seemed exhausted and was smoking more than usual.

Soon after, the faculty saw an opening and made him its best offer yet: Tenure upon hiring. A handsome salary, more than the $60,000 he was making in the State Senate or the $60,000 he earned teaching part time. A job for Michelle Obama directing the legal clinic.

Your political career is dead, Daniel Fischel, then the dean, said he told Mr. Obama, gently. Mr. Obama turned the offer down. Two years later, he decided to run for the Senate. He canceled his course load and has not taught since.

Now, watching the news, it is dawning on Mr. Obama’s former students that he was mining material for his political future even as he taught them.

Byron Rodriguez, a real estate lawyer in San Francisco, recalls his professor’s admiration for the soaring but plainspoken speeches of Frederick Douglass.

“No one speaks this way anymore,” Mr. Obama told his class, wondering aloud what had happened to the art of political oratory. In particular, Mr. Obama admired Douglass’s use of a collective voice that embraced black and white concerns, one that Mr. Obama has now adopted himself.

In class, Mr. Obama sounded many of the same themes he does on the campaign trail, Ms. Callahan said, ticking them off: “self-determinism as opposed to paternalism, strength in numbers, his concept of community development.”

But as a professor, students say, Mr. Obama was in the business of complication, showing that even the best-reasoned rules have unintended consequences, that competing legal interests cannot always be resolved, that a rule that promotes justice in one case can be unfair in the next.

So even some former students who are thrilled at Mr. Obama’s success wince when they hear him speaking like the politician he has so fully become.

“When you hear him talking about issues, it’s at a level so much simpler than the one he’s capable of,” Mr. Rodriguez said. “He was a lot more fun to listen to back then.”

Labels: Politics and African Americans