John G. Roberts, 50, is considered a GOP heavyweight amid the largely Democratic Washington legal establishment.

Roberts was appointed to the U.S. Court of Appeals for the D.C. Circuit in 2003 by President Bush. (He was also nominated by President George H.W. Bush but never received a Senate vote). He practiced law at Hogan & Hartson in the District from 1986 to 1989 and from 1993 to 2003.

From 1989 to 1993, he was the principal deputy solicitor general in the George H.W. Bush administration, helping formulate the administration's position in Supreme Court cases. In the Reagan administration, he was an aide to Attorney General William French Smith from 1981 to 1982 and an aide to White House counsel Fred Fielding from 1982 to 1986.

With his impeccable credentials -- Roberts attended Harvard College and Harvard Law School, clerked for then-Justice William H. Rehnquist Jr. on the Supreme Court and has argued frequently before the court -- the question marks about him have always been ideological. His GOP loyalties are undoubted, earning him the opposition of liberal advocacy groups, but he is not a "movement conservative," and some on the party's right doubt his commitment to their cause. His paper record is thin: As deputy solicitor general in 1990, he argued in favor of a government regulation that banned abortion-related counseling by federally funded family-planning programs. A line in his brief noted the Bush administration's belief that Roe v. Wade should be overruled.

On the D.C. Circuit, Roberts voted with two colleagues to uphold the arrest and detention of a 12-year-old girl for eating french fries on a Metro train, though his opinion noted, "No one is very happy about the events that led to this litigation." In another case, Roberts wrote a dissenting opinion that suggested Congress might lack the constitutional power to regulate the treatment of a certain species of wildlife.

-- Charles Lane