TONIGHT THE presidential campaign shifts from Iraq and foreign policy to the domestic issues that have, understandably, taken a back seat. That leaves CBS's Bob Schieffer, who will moderate the third and final debate, with a slew of topics to pack into a 90-minute session, including education, civil liberties, the environment and homeland security.

We'd begin with the selfish, even piggish behavior today's leaders are showing toward the next generation -- in other words, with the budget deficit and the growing burden that Social Security and Medicare will place on young workers as the baby boom generation retires. We'd begin specifically with President Bush's reckless tax cuts, which exacerbate that looming problem. Mr. Bush touts the cuts as "the fuel that got our economy growing again," but the consulting firm Economy.com, like many other economists, says that the "economic bang for the buck of the president's policies has been modest at best" and that a better-targeted tax cut could have had the same effect at a far smaller cost.

Mr. Bush argues that Sen. John F. Kerry's approach, which would sustain the tax cuts only for those making less than $200,000 a year, would hurt small-business owners and therefore harm job creation, because many small businesses pay taxes at individual income tax rates. But an analysis by the Urban Institute-Brookings Institution Tax Policy Center found that only 3 percent of taxpayers with business income would be affected -- and few of those are actually businesses with employees. If the small-business argument is bogus, as the evidence suggests, why does Mr. Bush insist on continuing those tax cuts in the face of record deficits?

Almost by default, Mr. Kerry is the fiscal conservative in the race, but over the past few months he has boxed himself in with unfortunate promises: not to cut Social Security benefits, not to raise taxes on the middle class. Why is Mr. Kerry's version of "read my lips" any more responsible than that of the first President Bush? During the Democratic primaries this year, former Vermont governor Howard Dean warned, "We cannot keep telling people we're going to give them all the programs they want and then there's not going to be any sacrifice." Isn't Mr. Kerry doing precisely that? If his health care plan turns out to cost not $653 billion over the next decade, as his campaign says, but closer to $1.5 trillion, as the Bush campaign maintains, what part will he cut?

Mr. Bush wants to let people invest some of their Social Security money in private accounts, but how would he pay for the $1 trillion or more that moving to private accounts would cost, at least in the short term? What happens if the market goes sour and retirees end up with less than they expected? On Medicare, Mr. Bush added a new prescription drug benefit to the program that piles on trillions more in costs over the long term; Mr. Kerry wants to make the drug entitlement even more generous. What would either candidate do as president to put Medicare spending on a sustainable course?

We hope the debaters also will find time, at last, for the topic of immigration; after all, the foreign-born population in the United States increased by more than half between 1990 and 2000. Mr. Kerry says he favors "earned legalization" for illegal immigrants -- but how would he then realistically deter millions more from crossing the porous border? Mr. Bush offered a promising, if sketchy, plan in January to make the country's roughly 8 million undocumented immigrants eligible for temporary legal status if they have jobs. But, in the face of resistance from conservatives, that plan has all but disappeared. Does Mr. Bush still support the plan, and, if so, why has he been silent?