How would candidate Obama answer professor Obama's exams? During his years teaching constitutional law at the University of Chicago, Barack Obama favored take-home tests touching on some of the scorchingly hot-button legal issues of the day: gay rights, reproductive freedom, affirmative action and racial profiling.

These exams, unearthed by The New York Times' Jodi Kantor, are edgy versions of the classic law school "issue spotter." Can a state university's law review expand its affirmative action program to include special treatment for gay students as well as racial minorities? Does a man have any right to stop his ex-wife from using their frozen embryos to try to get pregnant? Can parents whose daughter is in a vegetative state be prohibited from trying to clone her?

To read Obama's exams is to get a glimpse of the supple intelligence he would bring to the presidency and to be impressed by his lawyerly capacity to see the other side's argument and mine the weaknesses of his own case.

But it is also a reminder of Obama's essential elusiveness, and how little we understand about how the candidate would resolve these thorny problems.

For example, one 2003 question describes the state of "Nirvana," where a gay couple want a child. Would Nirvana's laws prohibiting gays from paying surrogate mothers or adopting children, Obama asked, violate the constitutional guarantees of equal protection and due process?

It's easy to imagine President Obama wrestling with a real-world version of professor Obama's hypothetical. Obama has said that he does not support same-sex marriage. But his exam question involves the same issues that the California Supreme Court addressed in overturning the state's same-sex marriage ban. If the Constitution protects the couple's effort to have a child, would it similarly protect their right to marry?

In the model answers he provided for students after another exam, Obama refers to "some persuasive arguments" that homosexuality should be covered by the Equal Protection Clause. How does that square with his opposition to same-sex marriage? Are civil unions a separate-but-equal substitute?

To take a 1997 question, should "Splitsville," a city plagued by residential segregation and failing schools, be permitted to create an all-black, all-male career academy, or is the "Ujamaa School" unlawful discrimination?

Even if constitutional, Obama asked, "is it good public policy? Put somewhat differently, in light of ... the history of race and gender discrimination in America, is the Ujamaa School a worthy attempt to promote long-term equality, or ... a dangerous betrayal of the American ideal?"

In model answers, Obama didn't tip his hand. Instead, he noted merely that "I did find it interesting that, based on a justifiable skepticism in the prospect of truly integrated schools and an equally justified concern over the desperate condition of many inner-city schools, a slim majority of you favored the idea of a Ujamaa-type program."

Another question to advise "Utopia" governor "Arnold Whatzanager" on a ballot initiative — a follow-up to one barring racial preferences — prohibiting the state "from classifying any individual by race, ethnicity, color or national origin."

Obama sought students' "broader perspective on whether the use of racial classifications by the state should in fact be rethought."

You can hear campaign trail echoes of Obama's efforts to grapple with this question. "I have a sister who is half Indonesian, who is married to a Chinese Canadian," he said the other day. "I don't know what that makes my niece."

Obama's part of the Con Law curriculum involved individual rights, so some of the constitutional issues most salient to a president — the separation of powers, the scope of executive authority — are not covered.

In one 2001 question, though, Obama asked students to imagine themselves as lawyers in the White House counsel's office, advising the president after an anthrax-like attack. Faced with a shortage of antibiotics, and given evidence that African-Americans and women were more susceptible to the toxin, how could the president allocate the medication?

The Obama exams provide no smoking guns for opposition researchers. Rather, they are fleeting snapshots reminiscent of Obama's approach in "The Audacity of Hope," even-handed in a way that is simultaneously impressive and maddening.

Reading them buttressed my confidence in Obama's capacity to grasp the nuances of any question, no matter how complex. They also underscored my sense that, in the hardest cases, I'm not always sure where professor Obama, or president Obama for that matter, comes down.

Ruth Marcus is a member of The Washington Post's editorial page staff. Reach her at marcusr@washpost.com.