While Senate confirmation of Judge Sonia Sotomayor seems a foregone conclusion, open debate over it in the Senate Judiciary Committee, if undertaken responsibly, can be a constructive exercise for the American public.

The makeup and deliberations of the Supreme Court are critical to the preservation or the deterioration of the principles by which we're governed.

Yet only when a vacancy on the court occurs is much broad public attention paid.

In presidential years, candidates labor in vain to convince voters that among the major stakes in how they vote will be who will be positioned to affect the future composition and judgments of the Supreme Court. When the court has an obvious philosophical split, as in recent years, the filling of a single vacancy sparks heavy argument over its direction.

The lesson of the importance of a presidential appointment to the highest court was emphatically underscored in its split decision awarding the presidency to George W. Bush, and all that happened in this country and abroad thereafter.

Special-interest groups, such as those on opposite sides of the abortion-rights issue, may have moderate success in getting supporters to cast their presidential ballots on their favored single interest. But most voters are swayed by other, and often inconsequential, factors.

Party affiliation is not as persuasive as in the past, but it does count with many voters, either out of longtime loyalty or affinity with political philosophy. Others simply apply a "likeability" test at the polls.

There was a time, too, when tradition and sentiment held that a president was entitled to his own choice of a Supreme Court nominee. Nothing short of some egregious personal failing was considered legitimate grounds for Senate refusal to confirm.

But particularly with the advent of television, Senate confirmation hearings have emerged as riveting entertainment of the most substantive order, drawing in viewers of every social and educational stratum. Nominees are obliged to discuss and defend their judicial qualifications, under detailed questioning about their philosophy and, increasingly, their personal lives and temperament.

This time around, Judge Sotomayor's sterling legal education and judicial experience are taken for granted. And the fact that she would be the first Hispanic-American to sit on the Court is an outcome that no self-preserving senator can ignore, even if they believe there are legitimate grounds to oppose her confirmation.

The judge has handed her conservative Republican critics an argument in commenting that being "a Latina woman with her experiences," she might well come up with "a better conclusion" in a case than "a white male who hasn't lived that life." Simplistic reactions from ideological purists like Newt Gingrich and Rush Limbaugh have suggested such a statement amounts to "reverse racism."

But more thoughtful conservatives have elevated the debate to whether application of such a rationale substitutes empathy toward society's disadvantaged for dispassionate decision-making. They argue for Chief Justice John Roberts' equating the latter approach with a baseball umpire calling balls and strikes.

Defenders of Sotomayor's view can note that an umpire is supposed to "call 'em as he sees 'em," and one umpire behind the plate may see the strike zone differently from another. The baseball analogy can be carried too far, but calling a pitch or deciding a case will doubtless be in the eye of the beholder.

President Obama in announcing Sotomayor's nomination made no mention of her ethnicity. But he did offer in her favor not only her impressive legal education experience "but the wisdom accumulated from an inspiring life's journey," a reference to her humble bootstrap beginnings.

Accordingly, directly or not Obama has asked the Senate to take where she came from into consideration. He has often said he wants a justice who will be open to decisions that will take the side of those who most need and deserve the administration of justice.

It's reasonable grounds for a reasoned debate over Sotomayor's confirmation, and if it takes place, an attentive public will be well served by it. Her supporters on the Senate Judiciary Committee should have no reluctance or difficulty in defending the notion that her heart as well as her head is in the right place.