People for the American Way has some good new background information posted on John Roberts:

John Roberts has been a judge on the U.S. Court of Appeals for the D.C. Circuit for only two years and was a corporate law firm lawyer for most of his career. He has a sparse public record, making it difficult to evaluate his fitness for the Supreme Court. Where he does have a record, however, Roberts fails to show a commitment to fundamental civil and constitutional rights, both in his role as a Deputy Solicitor General and judge.

School Desegregation
Roberts argued that Congress could pass a law preventing all federal courts from ordering busing to achieve school desegregation under any circumstances, a position even more extreme that that advanced by Theodore Olson and adopted by the Reagan Administration. (Memo from John Roberts, 2/15/84)

Access to Justice
Roberts argued that Congress should strip the Supreme Court of the authority to rule on cases regarding school prayer, abortion, busing for school desegregation, and other issues, a position even more extreme that that advanced by Theodore Olson and adopted by the Reagan Administration. (Washington Post, 7/27/05)

Affirmative Action
Roberts argued that affirmative action programs were bound to fail because they required "the recruiting of inadequately prepared candidates." (Washington Post, 7/27/05)

Voting Rights
Roberts helped promote the Reagan administration's efforts to severely limit the circumstances under which minorities could bring suit under the Voting Rights Act. (New York Times, 8/3/05)

Immigrants' Rights
Roberts criticized a Supreme Court ruling striking down a Texas law that had allowed school districts to exclude children of undocumented immigrants. (Washington Post, 7/27/05)

Civil Liberties
In a recently-decided case brought by a Guantanamo Bay prisoner, Judge Roberts joined a ruling holding that the government could try terrorism suspects without granting them basic due process protections. (Opinion in Hamdan v. Rumsfeld, 2005)

Religious Liberty
Roberts argued against clear First Amendment protections for religious liberty and in favor of officially sponsored school prayer at graduation ceremonies before the Supreme Court, which rejected his argument. (Amicus brief in Lee v. Weisman, 1992)

Title IX
Roberts argued to narrow the reach of Title IX, the law that prohibits sex discrimination in education programs that receive federal funding. (Washington Post, 7/27/05)

Sex Discrimination
Roberts argued that the Justice Department should not intervene on behalf of female prisoners who were discriminated against in a job-training program, contradicting even the views of extremely conservative Civil Rights Division head, William Bradford Reynolds. (Washington Post, 7/27/05)

Rights of the Disabled
Roberts criticized as "judicial activism" a court's order requiring a sign-language interpreter for a hearing-impaired public school student. (Washington Post, 7/27/05)

Rights of the Accused
Roberts sought to expand the ability of prosecutors and police to question suspects out of the presence of their attorneys. (Washington Post, 7/27/05)

Reproductive Freedom
Roberts urged the Supreme Court to overturn Roe v. Wade, the landmark decision granting women the right to choose. (Brief in Rust v. Sullivan, 1991)

Environmental Protection
As a judge, Roberts authored a dissent arguing that the Endangered Species Act may be unconstitutional as applied in that case.  Worse, this case indicated that he may subscribe to the very dangerous new "federalist" views of limited congressional power to protect the environment and the rights of individual Americans. (Dissent in Rancho Viejo, LLC v. Norton, 2003)

Executive Power
As a judge, Roberts has shown enormous deference to the executive and an expansive view of executive power.  In one case, for example, he would have gone farther than his colleagues on the court and allowed the Bush Administration retroactively to eliminate the jurisdiction of the federal courts to hear claims against Iraq by American soldiers who had been tortured there as POWs during the Gulf War, at a time when Iraq was considered a terrorist state. (Opinion in Acree v. Republic of Iraq, 2005)

Excessive Arrest Procedures
Roberts ruled against a 12 year-old girl who was handcuffed, arrested and taken away by police for eating a single French fry on the D.C. Metro, even though an adult would only have gotten a paper citation in that situation. (Opinion in Hedgepeth v. WMATA, 2004)