The Elena Kagan hearings were a sleepy affair. With no 12th-hour revelations and a candidate who acquitted herself as cagey and well qualified, the solicitor general proved adept at the kabuki dance of the Supreme Court confirmation process.

Yet there was one exception to the otherwise humdrum hearings: the bewildering decision by Republicans to taint Ms. Kagan by her association with Thurgood Marshall.

Yes, that Thurgood Marshall — Baltimore native, hero of the civil rights movement, mastermind of Brown v. Board of Education, and the first African-American Supreme Court justice.

If the senators had spent their time asking Ms. Kagan to indulge in fond reminiscences of her former boss, nobody would have blamed them. After all, Marshall is an American hero of the very first rank. But they didn't, and the reason is that they were determined to make the late Marshall their lead witness for President Barack Obama's "empathy standard."

You may recall that, before he nominated Sonia Sotomayor, the president called empathy "an essential ingredient for arriving at just decisions and outcomes" and thus an indispensable tool for U.S. Supreme Court justices. When it came to filling vacancies on the court, he said, a superior legal mind was necessary but not sufficient. He would choose nominees capable of "understanding and identifying with people's hopes and struggles" — nominees, that is, with a special gift for empathy.

After the president's announcement, Republicans immediately began climbing the barricades.

Utah's Sen. Orrin Hatch called empathy "a code word for an activist judge." Political commentator Charles Krauthammer declared, "if nothing else, [conservatism] stands unequivocally against justice as empathy — and unequivocally for the principle of blind justice." And Wendy Long of the newly rechristened Judicial Crisis Network accused Mr. Obama of aiming to "become the first president in American history to make lawlessness an explicit standard for Supreme Court justices."

Senate Democrats, for their part, did not exactly take up arms. Aside from a few muted protests in the Sotomayor hearings, they let the Republicans darkly define the word. More than anything else, it seemed, they hoped it would simply go away.

In his speech nominating Ms. Kagan, the "e-word" was unspoken, though Mr. Obama appeared to hint at it. He quoted Ms. Kagan's tribute to her former mentor, in which she said that Marshall liked to tell stories of his own pursuits of justice to remind his clerks that "behind law there are stories — stories of people's lives as shaped by the law, stories of people's lives as might be changed by the law."

This, said the president, showed that Ms. Kagan had an "understanding of law, not as an intellectual exercise or words on a page, but as it affects the lives of ordinary people," a compliment which, to Republican ears, was as good as saying that Ms. Kagan had a capacity for judicial empathy just waiting to be unleashed.

And so Thurgood Marshall became the unlikely bridge between empathy, activist judging, and Ms. Kagan. Noting the missing word in the president's nomination, Republican Sen. John Kyl of Arizona said Mr. Obama had merely "repackaged" the empathy standard. He still believed that "in some kind of cases, judges should abandon impartiality and instead engage in results-oriented judging." Marshall, he said, was the "epitome" of that view.

This, of course, is a caricature. The president has never said that judges should abandon impartiality. Instead, he's tried to call attention to the limits of legal certainty and the role empathy might play in confronting them. He did this first in a rebuttal to Chief Justice John G. Roberts Jr.'s "umpire analogy," where the chief justice famously compared the work of a judge to that of a baseball umpire. "Umpires don't make the rules," Justice Roberts observed in his own confirmation hearings, "they apply them."

Then-Senator Obama took on this rather uncomplicated view when he announced that he would not vote to confirm Mr. Roberts. "Ninety-five percent" of the time, he said, cases could be resolved by recourse to the "basic precepts" of judicial decision-making, the protocols of good behavior that nearly all judges follow.

Still, that left 5 percent, the "truly difficult" cases where the "[l]egal process alone will not lead you to a rule of decision." Contrary to the umpire analogy, such cases did not involve a straightforward application of the law, because what the law demanded was itself unclear. A judge, Mr. Obama said, had to rely on other resources to reach her decisions, including "one's deepest values, one's core concerns, one's broader perspectives on how the world works, and the depth and breadth of one's empathy."

Contrary to conservative conceit, this is not an unusual vision of the law. Justices as diverse as James Wilson, Oliver Wendell Holmes, Benjamin Cardozo, Sandra Day O'Connor, and, most recently, David Souter have all said something similar.

In fact, in the same tribute where Ms. Kagan said that Marshall "allowed his personal experiences, and the knowledge of suffering and deprivation gained from those experiences, to guide him," she also noted that he could be "quite the formalist" when the law was unequivocal.

Ms. Kagan described an instance where she and her co-clerks "pleaded" with Marshall to overlook a legal technicality in furtherance of a more just outcome. Marshall, she said, turned them down flat. "All you could hope for, he remarked, was that a court didn't rule against you for illegitimate reasons; you couldn't hope, and you had no right to expect, that a court would bend the rules in your favor."

Thus, the real debate underlying the empathy controversy is not whether judges can simply make up the rules (or the laws) as they go along. That's a straw man.

The debate is over the relative clarity of the law, especially constitutional law, and where a judge should look whenever the law is unclear.

To hear conservatives tell it, as Justice Souter recently said, "all of constitutional law lies there in the Constitution waiting for a judge to read it fairly." That thought may be comforting — certainty is almost always comforting, at least when it comes to the law — but it fails "to understand what judges have no choice but to do," which is to make a hard decision when the law won't make it for them.

If the president thought mothballing one simple word would exempt his nominees from this debate, the Kagan hearings proved him wrong. That debate will continue, and by failing to engage it, the president will not only deny judicial empathy and the wisdom of experience a powerful spokesman, he will help to ensure that Americans see them as the Republicans would have it — as enemies, rather than fierce advocates, of equal justice before the law.

John Paul Rollert teaches business ethics and leadership at Harvard Summer School. He is pursuing a JD at Yale Law School and a PhD at The Committee on Social Thought at the University of Chicago. This article originally appeared in The Christian Science Monitor.