n a presidential campaign defined by arguments about what to do with a massive budget surplus, candidates in both parties are looking to capitalize on the possibility of an even bigger windfall than previously expected.
Government projections due in the coming weeks are expected to show the cumulative federal surplus could be up to $800 billion larger by 2010 than the $3 trillion figure now commonly accepted, which includes $2 trillion in extra Social Security revenue.
Such projections are speculative, of course, and could prove to be off by hundreds of billions of dollars. But they have nevertheless served as the point of reference for presidential debates over tax cuts and spending plans.
And the notion that an incoming president will have extra billions of dollars at his disposal may give some candidates new freedom to expand their proposals, and others a chance to fend off criticism that they would overspend the surplus, damage the economy, and leave nothing in reserve for programs such as Social Security and Medicare.
The new figures ''will intensify the food fight'' over the surplus, said Robert Reischauer, a senior fellow at the Brookings Institution and a former director of the Congressional Budget Office.
The first estimates will be released later this month by the CBO. On Feb. 7, the White House Office of Management and Budget will release its figures.
Although the official projections are not due for weeks, and even as some economists warn against overstating their significance, they are already showing an impact on the campaign as the candidates seek to spin complicated budget figures to their advantage.
During Saturday's Democratic forum in Des Moines, former New Jersey senator Bill Bradley sought to neutralize one of Vice President Al Gore's favorite charges, that Bradley's sweeping health care plan would ''blow the surplus'' and leave no money to preserve Medicare, by citing reports of the new estimates.
''I think we can do both,'' Bradley said. ''The surplus over the next decade is going to be another $800 billion. So we can do both.''
Such a defense could prove invaluable for Bradley as he tries to fend off Gore's repeated attacks on the cost of his health care plan. Bradley estimates the plan as costing around $650 billion over 10 years. But Gore says the figure is closer to $1.2 trillion, greater than the current projected surplus of $1 trillion in non-Social Security dollars, and could lead to budget deficits.
Meanwhile, on the Republican side, the campaign of Arizona Senator John McCain says the rosier numbers are a factor behind a decision to expand McCain's tax cut plan, which he will outline tomorrow in Concord, N.H.
In June, McCain outlined a tax cut of $500 billion over 10 years, a size criticized by some Republicans as too modest compared with the proposal made by Texas Governor George W. Bush, who offered a $483 billion cut over 5 years.
In response, McCain has charged that Bush's tax cut would squander the surplus and leave no funds for Social Security, Medicare, or reducing the $5.8 trillion national debt.
But the McCain campaign now says higher revenues allow for a bigger tax cut. ''We will acknowledge the possibility of greater surpluses,'' a McCain aide said.
Some economists, however, caution that the new budget cushion could be far less than the $800 billion figure cited by Bradley. And they note that any estimates must be considered in the context of growing federal spending, an argument echoed by Gore in Saturday's debate.
''The people who make up the numbers say the natural growth in government services is going to take up almost all of that over the next 10 years,'' Gore said.
Most estimates so far have assumed that Congress would abide by strict spending limits it passed in 1997, but Congress has repeatedly broken those caps by tens of billions of dollars.
As a result, Reischauer said, surplus projections to date have been overly optimistic, leaving candidates on shaky ground as they now propose huge tax plans and spending plans for money that may well never materialize.
Thus, rather than providing a huge new cushion for candidates, Reischauer said, the end result may be nothing more than an affirmation of the $1 trillion figure currently relied on by most campaigns.
''Previously it wasn't a good number, but now it is,'' Reischauer said. ''These development are going to save the candidates from significant embarrassment.''
While the current $1 trillion figure describes only the portion of the surplus that does not come from Social Security, candidates of both parties say they will not borrow from extra Social Security funds.
The more optimistic figures will be based in part on new data from the Commerce Department's Bureau of Economic Analysis, and a recent slowdown in the growth of the expensive Medicare program for senior citizens.
Economists caution that any long-term estimates of economic growth are imprecise by nature, however.
''It's all very speculative,'' said James Horney, a senior fellow at the liberal-leaning Center for Budget and Policy Priorities in Washington. ''This is a very inexact science.''
Horney added that despite the ever-brightening economic news, dark economic clouds lie on the horizon.
''We have a serious budget problem in the years following all this,'' Horney said. In the years shortly after the surplus peaks, he said, baby boomers will begin retiring by the millions, putting an immense strain on the Medicare and Social Security programs.
''It would be good if in the debates over the next year people look more realistically at that long-term problem,'' Horney said.
