ROSS PEROT'S steamroller momentum is forcing critical decisions on the Bush and Clinton campaigns about which votes they are going to fight for.
In a normal election, the two parties fight over the great American middle, the independent or moderate voters most open to persuasion. Both major candidates seek to build a simple majority of electoral votes.
By now, the major candidates would have narrowed down the battleground states they will target for their campaign efforts to roughly 15 - in a normal election.
Not this year. The Perot phenomenon has swept away such comfortable efficiencies.
Both the Republicans and Democrats are debating a strategic choice: They can each shore up their eroded cores of supporters to the left and right, concede the middle to Mr. Perot, and strive to win with perhaps 40 percent of the vote. Or they can compete in the middle for a true majority of the popular vote.
Right now, both campaigns appear to be turning to their voter bases. "Suddenly, marginality sweeps across the whole country," says Democratic consultant Marc Siegel.
"Right now, we're competitive in states where we never would have been [without Perot in the race]," says David Carney, political director of the Bush-Quayle campaign. "But we're also behind Ross Perot in some of our base states."
Money is narrowing the options. In a three-way race of near-equals that could become a two-way race at some point - no one is sure which two - at least 30 states are wide-open targets. That spreads the parties' limited finances thin unless they narrow their aim.
In and around the Clinton campaign, strategists are considering concentrating in the South, for example, on turning out the black vote. Republican presidential candidates usually win two-thirds of the Southern white vote, but Governor Clinton could leave that group for Perot and President Bush to split if he turned out a strong enough showing of blacks and white liberals.
The Bush campaign has decided to build intensive volunteer networks in 300 strong Republican counties across the country this summer. Perot is running strong in affluent suburbs, which is Bush's base vote, and Bush needs to win those voters back.
Perot can easily outspend Bush and Clinton. He has said he will spend $100 million of his own and more if necessary. The two candidates that rely on federal funds are limited to $55 million each, plus another $10 million that their parties can raise and spend on their behalf.
But the dollars do not give the whole picture. The established resources of the major political parties probably put all three candidates at rough parity financially, according to Herbert Alexander, director of the Citizens' Research Foundation at the University of Southern California.
Perot's real advantage is that he is in complete control of his spending, Dr. Alexander adds. Much of the spending for the party candidates is by independent groups that the campaign itself cannot control.
Perot is also leading in the polls without any serious campaign spending. Through April, the latest available Federal Election Commission reports, he had spent just over $1 million - 85 percent of it his own money.
The Bush campaign appears to be more decided than the Clinton team that it must eventually seek an absolute majority to win. One reason is necessity: Perot supporters come more heavily from the ranks of voters who are traditionally Republicans.
"We're going for 50 percent," Mr. Carney says. Some states may be won with less, and Bush could be competing against a different chief opponent in different states, he says, "but 35-percent scenarios are ridiculous."
Yet another Republican strategist and presidential-campaign veteran, Vince Breglio, speculates that Perot's support will fade to no lower than 20 percent. That leaves the other candidates little more than their traditional party bases. "My guess is that something in the low 40s probably wins this campaign," he says.
The argument is louder on the Democratic side. Clinton's decision is less clear and fraught with rumors of impending campaign resignations over a turn to the left. Clinton's direction may not be entirely clear until the national convention in mid-July.
WILL MARSHALL, director of the Progressive Policy Institute, a moderate Democratic think tank with Clinton connections, sees a left turn as a "big mistake." He sees a choice between a broad strategy appealing to the middle class or a three-way split strategy that attempts to revive the party's "shriveled base."
Clinton "has to disassociate himself with what people don't like about both parties, not just the Republicans," Mr. Marshall says. Both Clinton and Perot are competing for the mantle of change and reform, for the role of chief alternative to Bush and the status quo. "Perot is occupying territory where Clinton needs to be," he says.
On the other hand, a Democratic candidate's most reliable supporters are in the party's left wing - especially blacks - and their turnouts were unusually low in the primaries this year.
Mr. Siegel, the Democratic strategist, sees both major candidates erring in turning away from the center. "It marginalizes them," he says, and the idea that either can rely on their traditional base of support is "fantasy."
All of these decisions are shots in the dark now. Few in either party believe that even the general shape of the campaign will emerge from the fog before late August, if then. Siegel believes that by October the campaign will dissolve into a two-man race.
If either major candidate falls back and wins less than 25 percent of the vote, his party will lose federal funding for the general election in 1996, a devastating blow to its future.