THE TENURE OF John G. Roberts Jr. as a judge has been brief and not terribly illuminating about what his work would be like as a member of the Supreme Court. Democrats can thank their own obstructionism for this lack of clarity. Judge Roberts was first nominated to the U.S. Court of Appeals for the D.C. Circuit by George H.W. Bush, but his nomination was stalled and then killed by Democrats when President Bill Clinton took office. Instead of spending a decade amassing a record that liberals could now examine, Judge Roberts worked as an appellate lawyer. The brief period he has spent on the court of appeals since the current President Bush revived his nomination offers little grounds for judgment about what sort of justice he would be.

It has, to be sure, provided few opportunities for radicalism. The D.C. Circuit is among the more collegial federal appellate courts in the nation. Despite a broad political spectrum among its judges, dissents are rare. Its judges generally work far harder than do the justices to achieve consensus. Judge Roberts has been in no sense an outlier. He has neither dissented much nor provoked much dissent, and where he and other judges have disagreed, there have generally not been substantial ideological overtones to that disagreement. According to one analysis of his voting record, he has agreed with Judge David Tatel -- perhaps the court's most liberal member -- 94 percent of the time. This reflects both the relatively apolitical nature of much of the court's caseload and the fact that Judge Roberts -- and, for that matter, Judge Tatel -- is appropriately sublimating his political views to apply the law.

Nor do the decisions for which he has been criticized, in general, raise concerns. Yes, Judge Roberts was a member of a recent panel that unanimously overturned an earlier district court opinion stopping the military tribunals at Guantanamo Bay; but the district court opinion had serious flaws, and the circuit court ruling was hardly a surprise. Judge Roberts, in addition, wrote for a unanimous panel that rejected a civil rights claim on behalf of a 12-year-old girl arrested for eating a french fry in the Metro system. The incident was outrageous, but the legal claim in response was weak.

Finally, Judge Roberts has been criticized for his vote to throw out a lawsuit by former American prisoners of war against the government of Iraq. This criticism is most unfair. The decision to dismiss the case was a unanimous one in which Judges Tatel and Harry Edwards joined; Judge Roberts disagreed with them only about the reason for dismissing the case, and his rationale is perfectly respectable. In general, Judge Roberts's work on the court has been elegantly crafted, legally precise and of very high quality.

There is really only one opinion Judge Roberts has written that potentially signals anything of serious concern, and that is the first one he wrote while on the court. The opinion is troubling because it suggests a too-narrow view of Congress's power to regulate interstate commerce -- the constitutional backbone of the modern regulatory state. Judge Roberts questioned whether the commerce clause of the Constitution is broad enough to permit the federal government to protect an endangered species that lives within a single state. But it would be a mistake to read too much into this opinion. Because of the procedural position of the case, Judge Roberts merely sketched his concerns and was careful not to pass judgment on the merits of the matter. The decision may be suggestive, but it hardly commits him to a particular philosophy as a justice in this important area.

Judge Roberts's work as a judge is too brief to recommend him especially highly as a justice; his main qualification is his long and excellent career as a practitioner. But neither will mining it yield anything disparaging. His two years on the D.C. Circuit have been a credit to it.