With moral and cultural issues playing as large a role in influencing tomorrow's presidential election as security, money and war, the question over the future make-up of the US Supreme Court is the issue that neither candidate has wished to fully acknowledge.
Beyond the prospect that disputed results in many states could once again put the outcome of the election in the hands of nine aging justices, the next president is almost certain to have the power to affect the ideological balance of the court, which often divides five to four on controversial issues.
With America's moral and cultural armies squaring off over gay marriage, stem-cell research and abortion, the power to appoint one or more new justices to the ideologically divided court is perhaps more important in the long term than who sits in the White House.
Last week, the issue came into focus when it was announced that 80-year-old Chief Justice William Rehnquist was being treated for thyroid cancer. Rehnquist, an ideological conservative who has presided over the court for 17 years and who has seen the country move to the right since he was appointed by former president Nixon, is said to be ready for work next week in case there are election issues to resolve.
But Rehnquist's illness placed both sides of the US' cultural divide on notice. Three other justices have already been treated for cancer, and with all but one over the age of 65, the court is fast approaching a changing of the guard that makes the outcome of tomorrow's vote all the more important.
It's 10 years since the last justice was confirmed; not since 1812 to 1823 has it gone that long unchanged. Indeed, some commentators fear Kerry's first or Bush's second term could be dominated by nomination battles. Democrats see the court as dominated five to four by conservatives; Republicans see it as evenly split. Any change in the make-up could tip it further either way.
"This election is not just about the next four years but the next 40," says Nan Aron, president of Alliance for Justice.
"The new president or the re-elected president will have huge control over the future direction of the court," Aron said.
Democrats fear that if Bush is re-elected, he will follow a familiar pattern of judicial appointment.
"Ideology has triumphed qualification in Bush's judicial selections," Aron said. "He's looked for young ideologues with fixed hostilities toward civil rights, environmental and consumer protections and a woman's right to choose."
Despite his faith, Kerry has vowed he will not nominate a judge who does not support abortion rights. Bush, somewhat opaquely, says he'll name "judges who know the difference between personal opinion and the strict interpretation of the law."
Under a Bush second term Democrats fear a conservative could be selected to replace liberal John Paul Stevens, 84. And conservative groups fear a liberal successor to Rehnquist or to the committed conservative Antonin Scalia.
"I don't think it is too much to say that the culture may well hang in the balance with the appointment of Supreme Court justices in the coming years," said Tony Perkins, president of the socially conservative Family Research Council.
As an original opponent of abortion rights and supporter of invading neutral Cambodia in the early 1970s, Rehnquist has been a soldier for the right, helping to deliver the 2000 election to Bush, weakening the barrier between church and state, restricting the criminal appeals process and the reach of affirmative action, as well as reducing the power of Washington to dictate to the states.