Why shouldn't candidates be asked to name some people they have in mind for the Supreme Court? The four current justices who constitute the court's liberal wing are ages 69, 70, 75 and 88. Swing voter Anthony Kennedy is 72. Odds are that at least one or two of these seats will need filling by the next president, and one of the four conservatives (average age: 60) might need replacing too.

Considering that one of these two men will soon be president, there is a great deal about their thinking that we should know and don't.

Let's allow that the second presidential debate between Sens. McCain and Obama was serious and reasonably dedicated to policy. The "town hall" format also allowed both men to move about and get face to face with individual citizen questioners, even if it did not prove as friendly to McCain as he might have hoped.

But neither the format nor the mood of the citizen questioners allowed for the full menu of issues we had been promised.

Sure, it was inevitable that economics would dominate. The country is in shock over the credit crunch and looming recession, the plunge in home and portfolio valuations.

But in their eagerness to address Issue One, NBC and Gallup chose questions and questioners fixated on it to the virtual exclusion of everything else. The only substantive news of the night occurred when McCain committed himself to buying most of the nation's troubled mortgages, a sweeping proposal he said would cost $300 billion.

That idea has been discussed in recent weeks as the crisis has worsened. The Bush administration and congressional leaders decided it was more efficient to buy up the mortgage-backed securities that have gone sour with the bursting of the real estate bubble.

Energy and health care did make cameo appearances, but primarily in the larger context of Americans' economic well-being. A question about asking Americans for sacrifice was treated as just another chance to talk about shielding us all from financial storms.

Toward the end of the 90-minute event, the subject was changed briefly to Iraq, Iran, Israel, Russia and the candidates' admitted inability to foresee the future. Then it was closing statements and good night.

Even when questioners attempted to get down to cases, the candidates nimbly eluded their grasp. For his part, moderator Tom Brokaw of NBC proved unwilling to enforce the questioner's point.

For example, one questioner via e-mail asked who might be the next secretary of the Treasury, a post of unprecedented power of economic decisions under the new enacted rescue plan for the financial industry. Neither candidate seemed eager to respond. McCain mentioned billionaire investor Warren Buffett, admitting he was an Obama supporter. Obama said he thought "Warren" would be a good choice but that there might be others. He named no one and went on to make another point.

McCain also mentioned Meg Whitman, former CEO of eBay, who for a time was cited as a potential vice presidential candidate (before Sarah Palin got the gig).

Want to make odds on either Buffett or Whitman winding up at Treasury? These are more like the kind of names you hear when a prospective president does not want to name the people he's really thinking about.

But key appointments will drive the next government, and voters should demand to know more about who they are likely to be. Why not tell us about your short list for State and Defense? And after the struggles of the past eight years, knowing who the next attorney general will be would make sense too.

For that matter, why shouldn't candidates be asked to name some people they have in mind for the Supreme Court? The four current justices who constitute the court's liberal wing are ages 69, 70, 75 and 88. Swing voter Anthony Kennedy is 72. Odds are that at least one or two of these seats will need filling by the next president, and one of the four conservatives (average age: 60) might need replacing too.

Yet we know only that McCain would appoint people like President Bush's two successful appointees and Obama would favor the kind of jurist appointed by Bill Clinton (the only Democrat to have had the opportunity in more than 40 years). That's a general contrast, to be sure, but not much more.

Of course, neither candidate wants to stir a distracting squabble over the qualifications of the people he may be considering. By the same measure, neither candidate wants to talk about immigration, because even a cautious formulation will cost votes either among Hispanics or among Anglos upset by those present in the country illegally.

What would either candidate do about the expiring No Child Left Behind Act? How about the faith-based initiatives sending tax money to religious institutions to perform nonreligious functions? Are there conditions under which the nation's defense might require reinstatement of the military draft, and if so, would it apply to women? Is it possible to contemplate a continuation of the Bush doctrine and current levels of forward deployment without a draft?

The salience of the economy as an issue has eclipsed the issues of Iraq and the war on terrorism. Indeed it has obscured the entire range of other issues, much as in the 1930s when all was subsumed in the Great Depression.

The single-issue phenomenon seems for the moment to be Obama's friend. But it is not really the voters' friend. It narrows the campaign's process of candidate discovery to a single obsessive concern, depriving the country of its best chance to find out just what its next leader really has in mind.

1:28 - October 8, 2008