The court has been willing to step into state election disputes, most notably the 2000 Bush v. Gore ruling that ended Florida recounts and effectively called the election for George Bush.

An announcement is expected soon on a request by Nader supporters for an emergency stay that would require Oregon to stop printing ballots that lack Nader's name.

The high court has been able to take up cases and rule quickly before elections. In 1968, it took the court about a week to hear arguments and rule that Ohio had to allow former Alabama Gov. George Wallace on that state's presidential ballot. Four years ago, the court heard two disputes arising out of the Florida presidential race deadlock. The decisive case was settled in less than a week.

Richard Hasen, an election law expert at Loyola Law School, said that after 2000, ''many people predicted the court would be a little gun-shy, but the court's been remarkably aggressive in the election area.''

Over the past year, the court has considered campaign spending restrictions and political map drawing.

''The court wants to make sure a candidate with a serious chance of success is not kept off the ballot,'' while giving states discretion to set their own candidate rules, he said, adding that Nader has a tough case to make.

Four years ago, Nader received 5 percent of the vote in Oregon as the Green Party nominee.