To the extent that Supreme Court reporters have any social utility at all, they're awfully useful when high-court vacancies pop up. Suddenly, everyone in the carpool wants to see your shortlist. Sadly, all the insider knowledge in the world—about the appeals courts or the rock stars of legal academia—reveals almost nothing about who will replace Justice David Souter on the high court next October. For that, you need an MRI machine. Because I'd wager that the most interesting infighting about the Constitution and the courts right now is taking place between the two hemispheres of Barack Obama's brain.

We already know that as a former constitutional law professor, Obama cares deeply about the courts. We also know, as Press Secretary Robert Gibbs says, that when it comes to picking the candidate, "this is a decision that he alone will make." As a decision that will reflect on Obama for decades to come, it may well reveal more about his values and preferences than the constitutional wobbles, dodges and reversals that have characterized his first months in office.

Unconstrained by the demands of national security, with this Supreme Court pick Obama finally has the chance to be bold. He has the opportunity to name someone who will deliver a much-needed defibrillating to the intellectually exhausted left wing of the court. Everyone—including me—has been expecting Obama to name a respectable incrementalist to slide into Souter's respectable incrementalist shoes. But I am more and more apt to think he might just shock us all in the coming days with someone ready to take up the mantle of Thurgood Marshall and William Brennan.

First, he needn't fear the filibuster. Moreover, it's clear that a moderate, minimalist technocrat will face the same rump-blistering confirmation as a liberal bomb-thrower. (The Judicial Confirmation Network has launched a series of ads trashing the moderate Solicitor General Elena Kagan, the more outspoken Judge Diane Pamela Wood of the Seventh Circuit Court of Appeals and the somewhat more outspoken Sonia Sotomayor of the Second Circuit in about equal measure.) The game of destroying Obama's nominee has little to do with the nominee. Whoever he or she might be, the actual name won't matter in the race to tarnish him or her as a hysterical, abortion-loving activist.

For all the president's talk of judicial "empathy"—a crazy-making term that's come to mean something different to everyone hearing it—Obama wasn't signaling his preference for a liberal version of Justice Antonin Scalia when he used it. He simply wants judges who are capable, as he explained in The Audacity of Hope, of accepting "the possibility that the other side might sometimes have a point." As my colleague John Dickerson explained in Slate, empathy isn't merely the quality Obama most admires in a Supreme Court jurist. It's also the quality he prizes most in himself.

Obama is at his most pragmatic and centrist when there's an argument on the other side for which he feels respect. Which means that his decision to make a bold statement with the Souter seat may turn on how much Obama "empathizes" with the political right on the role of the federal judiciary.

We have a few clues on that front: when then-senator Obama voted against then-lawyer John Roberts's Supreme Court confirmation in 2005, he contended that despite Roberts's qualifications, Obama had concerns about "the depth and breadth of his empathy" and the fact that throughout his career, Roberts chiefly used "his formidable skills on behalf of the strong in opposition to the weak." Although he publicly agonized over the decision, Obama was unequivocal in stating that the high court plays an important role in leveling the playing field between strong and weak. He didn't express the hope that he would come to appreciate Roberts's constitutional world view. He said he hoped Roberts would someday embrace his.

Last year, writing in The New Republic, one of the president's most trusted legal advisers, Cass Sunstein, described Obama as a "visionary minimalist"—someone who combines a bold vision for the country with a regard for political processes. Obama wants to push the country toward dramatic change while forging ideological consensus. Which suggests that if there is one Supreme Court candidate who's both a bold seer and a pragmatic centrist, his name might be Barack Obama. And he already has a job.

We'll know soon whether Obama favors a careful feather-smoother who can nudge swing Justice Anthony Kennedy subtly to the left, or an unrepentant liberal with Scalia's ability to write for the ages. As the whispers of White House interviews continue, it appears that Wood, of the Seventh Circuit, is at or near the top of Obama's list. Wood has gone toe-to-toe with the brilliant conservatives on that court for years now and more than held her own. If Obama picks her or one of the academic stars on his list, like Stanford's Pamela Karlan or Kathleen Sullivan, we will have new proof that while he can compromise on most anything and listen tirelessly to the other side, when it comes to the Supreme Court, the visionary minimalist will opt for visionary after all.

Lithwick writes a column about the Supreme Court and legal affairs for slate.com.

© 2009