Last week's confirmation hearings for Supreme Court nominee Sonia Sotomayor included much of what we expected: Probing questions from Republicans on hot-button culture war issues such as abortion, gay marriage, gun control, race, and affirmative action; and deference, deflection, and fawning praise from Democrats. Almost entirely left out of the discussion was a subject you might think has some relevance to the Supreme Court: the criminal justice system.

Determining the extent of constitutional protections for suspects and defendants may well be the Supreme Court's most important task. The framers of the Constitution thought so: four of the 10 amendments that make up the Bill of Rights lay out explicit protections for criminal defendants. Yet even though the Court has addressed a number of important Fourth, Fifth, Sixth, and Eighth Amendment cases in recent years, Sotomayor was never seriously challenged on her record of criminal justice jurisprudence. The few times these issues were broached at all, it was in the form of a friendly question from a Democrat, phrased to demonstrate that Sotomayor will be as tough on crime as any Republican appointee.

Sen. Chuck Schumer (D-NY), for example, noted with satisfaction in his introductory comments that over the course of her career, Sotomayor has "ruled for the government in 83% of immigration cases, in 92% of criminal cases." Sen. Amy Klobuchar (D-Minn.), a former prosecutor, used a portion of her Q&A with Sotomayor to highlight and praise instances in which Sotomayor was willing to excuse police officers who violated the Fourth Amendment. Democrats on the Senate Judiciary Committee also brought in law enforcement officials to testify in support of Sotomayor, including former Manhattan District Attorney Robert Morgenthau, former FBI Director Louis Freeh, and a representative from the Fraternal Order of Police. Republican members didn't call a single witness to critique Sotomayor's record on crime from the right. No wonder some criminal defense attorneys are worried.

One person neither party asked to testify is Jeffrey Deskovic, who was convicted at age 17 of a rape and murder he didn't commit. In 2000, Sotomayor and another judge on the 2nd Circuit Court of Appeals issued a curt, two-page ruling that refused to even consider Deskovic's innocence claim because his attorney filed four days late (the attorney says he was given bad information by a court clerk). "We have considered all of petitioner-appellant’s remaining arguments and find them to be without merit," the opinion read. Deskovic, who had already served 10 years, went on to serve another six before DNA testing led police to the actual killer. In a moving essay earlier this month, Descovic asked to be heard.

I want my case to be a part of the national discussion. I want Senators to ask Judge Sotomayor if she stands by her ruling, and whether she would rule that way in the future. If I could I would testify at the Senate confirmation hearing, about the human impact of Judge Sotomayor's putting procedure over innocence. Thus far, however, I have gotten no response from either side on Capitol Hill.

Last month, Vice President Biden told a gathering of law enforcement organizations that Sotomayor "has got your back," a startlingly inappropriate (even for Biden) assurance about a potential Supreme Court justice. Imagine the uproar if the vice president had said the same thing to the National Association of Criminal Defense Lawyers.

But Biden isn't the only one to share that assessment. Sotomayor's confirmation has been endorsed by eight major law enforcement groups. The L.A. Times reported last month that according to former colleagues, Sotomayor's time as a "zealous prosecutor" made her into "something of a law-and-order judge, especially when it comes to police searches and the use of evidence." New York criminal defense lawyer Gerald Lefcourt said Sotomayor "always seemed to be leaning toward the government," adding that she was "very police-like. Dismissive of what the defendant had to say about anything." Slate's Emily Bazelon also reported on one extraordinary case in which Sotomayor was able to convince a more conservative 2nd Circuit judge to join her in overturning a jury verdict against an off-duty police officer accused of threatening and assaulting a truck driver, on grounds that even off-duty cops have broad powers to make arrests.

If a Republican nominee had such a criminal justice track record, leftist advocacy groups would probably be up in arms—or at least concerned. And rightly so. But even criminal justice groups have been conspicuously quiet. The American Civil Liberties Union did publish a thorough review of Sotomayor's judicial record, but has maintained a sort of passive support for her nomination. Executive Director Anthony Romero said that although "the ACLU does not officially endorse or oppose US Supreme Court candidates, I have never been personally prouder of any appointment." Romero must have a short memory. The ACLU explicitly opposed Samuel Alito in 2006, and was publicly critical of John Roberts in 2005.

This is all the more troubling given the critical role Sotomayor will likely play on key criminal justice cases during her likely tenure. In the last term alone, there were six crime cases in which the defense position won on a 5-4 vote, with departing Justice David Souter casting a vote with the majority. In one of those cases, Melendez-Diaz v. Massachusetts, the Court held that the Sixth Amendment's Confrontation Clause gives criminal defendants the right to cross-examine any forensic expert whose work is submitted as evidence, a particularly important decision given a damning report on the reliability of forensic science issued earlier this year by the National Academic of Sciences. The decision has already sent shockwaves through the criminal justice system.

But just before ending its most recent term, the Court agreed to hear a case from Virginia (PDF) that raises similar issues regarding DNA testing. This has led some Court watchers to speculate that the minority in Melendez-Diaz sees Sotomayor as a potential ally who may join them to limit the scope of—or even overturn—last term's ruling. Sen. Klobuchar did ask Sotomayor about Melendez-Diaz, but only to express her disappointment with the ruling and her hope that the Court, presumably with Sotomayor's help, will overturn it. Sotomayor gave a typical confirmaiton hearing answer, acknowleding Klobuchar's concerns, stating that Melendez-Diaz is now established law, but ultimately refraining from speculating on how or whether she might limit its impact.

The New York Times reported in January that the Court is inching ever closer to eliminating or rendering impotent the Exclusionary Rule, which bars evidence obtained through illegal searches from being admitted at trial. Chief Justice John Roberts, the paper explained, is a longtime opponent of the rule, having led a campaign to repeal it as a young attorney in the Reagan administration. Replacing Souter, a fairly reliable defender of the Exclusionary Rule, with a former prosecutor like Sotomayor will likely at least narrow the rule’s application. Wall Street Journal reporters Jess Bravin and Nathan Koppel came to a similar conclusion last month, writing that while Sotomayor "stands in the liberal mainstream on many issues, her record suggests that the Supreme Court nominee could sometimes rule with the top court's conservatives on questions of criminal justice."

Content-free as they were, last week’s hearings were a tidy composite of the national debate over criminal justice issues. Which is to say that there really isn't any such debate. By conventional wisdom, defendants’ rights have traditionally been a concern only of the left. But you'd never know that by observing national politics. Criminal justice activists are fond of saying that Republicans are evil, but Democrats are spineless. That's not entirely accurate. Democrats such as Biden have been plenty active in dismantling constitutional protections against police power. Some of today's most draconian federal crime statutes were authored by Democrats.

Even as DNA testing has exposed serious flaws in a process once believed to be mostly (or at least tolerably) just, politics still really only affords one acceptible position on crime: We need to get tougher on it.

It's possible that worries over Sotomayor’s tough-on-crime jurisprudence are misplaced. Perhaps thus far in her career, her written opinions were bound by existing case law and procedural rules, and that as a precedent-setting Supreme Court justice she'll prove to be a staunch defender of the Exclusionary Rule and the Confrontation Clause, and her sensitivity to innocence claims will be sharpened by cases like Jeffrey Deskovic's.

It's possible. The problem is that we really have no idea. Because no one bothered to ask.

Radley Balko is a senior editor at Reason magazine.