Controversy over the American Bar Association’s ratings of potential judicial nominees is likely to continue with the announcement that the bar group will resume its role of evaluating candidates before their nominations.

In fact, a soon to be released study by three political scientists alleges what conservative groups have long charged: The ratings are biased against potential conservative nominees.

Political scientists Richard Vining of the University of Georgia, Amy Steigerwalt of Georgia State University and Susan Smelcer, an Emory University doctoral candidate, will present their findings next month at the Midwest Political Science Association’s 67th Annual National Conference.

The three academics, all of whom specialize in studying the intersection of the courts and politics, examined every nominee to the federal courts of appeals from 1985 to 2008, regardless of whether the nominee was confirmed or had a confirmation hearing.

Their study examined two hypotheses: First, the ratings are biased and favor nominees nominated by Democratic presidents, and, second, key professional qualifications affect the ratings — for example, whether the nominee has judicial experience, or is a practicing attorney or law professor. They looked at the party of the appointing president and constructed an ideology measure for the nominees and a model to explain the roles of experience, career path, education, race/gender and political affiliation in ABA evaluations.

“We do find evidence of at least some bias against Republican nominees,” said Steigerwalt. “However, we also find that the ABA clearly bases its ratings on a nominee’s professional qualifications — those who have more previous experience as state or federal district court judges receive higher ratings, as do those who have more experience as a government attorney. Based on the totality of these findings, we conclude that the ABA plays an important role in rating the professional qualifications of potential nominees, but that it must also work to ensure that its ratings remain free from any type of ideological bias.”

The ABA was not immediately available for comment on the study, but ABA President H. Thomas Wells Jr., in the recent announcement last week that the Standing Committee on the Federal Judiciary would evaluate potential Obama administration judicial nominees, said that ideology plays no part in the evaluation process.

In 2001, the Bush administration announced it would no longer submit names to the committee in advance of nominations. The break with tradition was the result of increasing criticism by conservative groups and Republican senators, who claimed that the evaluations were infected with political bias.