IN THE SECOND DEBATE, an issue of obvious importance finally came up, in a question put to President Bush: “If there were a vacancy in the Supreme Court and you had the opportunity to fill that position today, who do you choose and why?” The question was smartly asked, not least because it began with that word “if.”

There hasn’t been a Supreme Court vacancy since Justice Harry Blackmun stepped down in 1994. The court’s vacancy drought, if it extends through 2006, will surpass the longest, recorded 180 years ago when a smaller court went almost 12 years with the same cast.