WASHINGTON -- Like at least four other members of the U.S. Supreme Court yesterday, Justice John Paul Stevens seemed to be trying to define when campaign contributions lead to an appearance of bias requiring a judge to step aside to ensure a fair trial.

The case argued before the Supreme Court involves a high-stakes election so riveting that novelist John Grisham used its underpinnings for the best-selling book The Appeal.

The case involves $3 million spent by a West Virginia coal executive to help elect a state Supreme Court justice who, after taking the bench, was a crucial vote in overturning a $50 million-plus verdict against the company.

But a ruling by the Supreme Court could shape state judicial races nationwide, including often-expensive Ohio Supreme Court elections.

One indication of the importance of the outcome: Among those filing legal briefs in an attempt to sway the ruling were Ohio Supreme Court Justice Evelyn Lundberg Stratton and Ohio Citizen Action, a nonpartisan advocacy group.

Stratton, who has reaped nearly $3 million in contributions for her three statewide campaigns, said appointed judges also can have their impartiality questioned and that people back judges on the basis of general philosophy, not to try to buy their votes on specific cases.

But Ohio Citizen Action says all that fundraising makes Stratton and other Ohio Supreme Court justices indebted to big contributors whose interests come before the court's.

Stevens, three other liberal-leaning justices and Justice Anthony Kennedy, who is often a swing vote on the nine-member court, appeared sympathetic to the latter argument.

"Our whole system is designed to ensure confidence in our judgments," Kennedy said.

The problem might come, some justices indicated, in figuring out how to establish a system that wouldn't open up a floodgate of attempts to force judges off cases based on direct campaign contributions, independent group spending -- such as the effort heavily financed by the Massey Energy Co. executive in West Virginia -- newspaper endorsements or union get-out-the-vote drives.

Justice Antonin Scalia and Chief Justice John Roberts expressed skepticism about whether a constitutional right to a fair trial is violated by the mere appearance or probability of bias.

Scalia said he does not favor a "constitutional rule that is a sliding scale," where one set of potential conflicts lead to another possible appearance of impropriety. Roberts said he worries about parties gaming the system by making "protective donations" simply to keep judges from hearing certain cases.

But Stevens said that the circumstances surrounding the West Virginia case were so extreme that it could lead someone to question whether a fair trial was possible. Stevens cited former Justice Potter Stewart's famous line about defining obscenity: "I know it when I see it."

That was the essence of the argument offered by Theodore Olson, the attorney for Hugh Caperton, president of Harman Mining Co., the other party in the Massey lawsuit.

The plaintiffs contend that West Virginia Supreme Court Justice Brent Benjamin should have taken himself off the case -- an appeal of the huge verdict that Harman won against Massey -- after defeating a sitting justice in a campaign dominated by independent spending by Massey executive Donald Blankenship.

Those circumstances precluded Caperton from receiving a "fair trial in a fair tribunal," said Olson, a former federal solicitor general in the Bush administration. "That means not only the absence of actual bias, but a guarantee against even the probability of an unfair tribunal."

But Andrew Frey, Caperton's attorney, said nothing prevented Benjamin from making a fair decision. "I ask the court to ask yourselves, if you were in Justice Benjamin's situation, do you really think you would be incapable of rendering an impartial decision in a case involving Massey?"

jriskind@dispatch.com