The Democratic Party faces a tough two-year comeback effort, with a weakened president, a resurgent opposition and the ever-present danger of a party-splitting civil war.

The situation confronting President Clinton and his party has ominous historical antecedents. After less devastating midterm losses than their party suffered last Tuesday, the last two Democrats in the Oval Office, Lyndon B. Johnson and Jimmy Carter, tried to readjust their policies but failed to regain political equilibrium.

The 1978 Democratic losses were relatively modest: three seats in the Senate and 15 in the House. In 1966, Democrats lost four Senate seats and 47 House seats from their big majority. In both cases, they kept control of Congress.

White House aides dismissed the notion that in 1996 Clinton may follow Johnson, who retired rather than seek reelection in 1968, or Carter, who beat back a challenge by Sen. Edward M. Kennedy (D-Mass.) for nomination but lost the 1980 election to Ronald Reagan. That is "sheer speculation with no basis in fact," one senior adviser said.

The applicable precedent, the presidential aides said, is Harry S. Truman, who saw Republicans capture Congress in 1946 and turned the tables on them by winning the 1948 election and restoring Democratic control of Congress.

Tony Coelho, the former House member who is one of the president's outside political advisers, said Friday, "There is no need to panic. On the breadbasket issues, like reducing the deficit, increasing jobs and keeping the economy moving, the president is very credible. What he needs to do is stay focused in those areas where he's credible, and let the Republicans deal with reform of Congress and trying to implement that 'contract' they signed with the American people."

Still, no one around the president disputes that Clinton faces a steeper climb to victory in 1996 than any of them anticipated before Tuesday's landslide produced Republican majorities in both houses of Congress and in the nation's governorships.

An NBC News-Wall Street Journal poll taken immediately after the midterm voting showed Clinton losing to the new Senate majority leader, Robert J. Dole (R-Kan.), by 45 percent to 39 percent.

Analysis of Tuesday's returns demonstrates even more clearly than that instant poll how the electoral odds have tipped against Clinton, especially if the 1996 election turns out to be a two-way race, uncomplicated by Ross Perot or some other significant independent candidate.

In 1992, Clinton won a plurality victory, gaining 43 percent of the popular vote, to George Bush's 38 percent and Perot's 19 percent. In electoral college votes, Clinton prevailed over Bush, 370 to 168, with no state going to Perot.

For both parties, the main political game for the past two years has been wooing Perot supporters. Tuesday's exit polls showed that the GOP came out on top by a lopsided margin. Fully 65 percent of those who said they had backed Perot in 1992 voted for Republican congressional candidates this year.

As the accompanying maps show, allocating 65 percent of Perot's 1992 support to the Republican presidential candidate moves 10 states with 91 electoral votes from Clinton's column to the GOP side, leaving the president with 279 electoral votes -- just nine more than needed for victory.

But there is worse news for the president from the 1994 election. Last time, Clinton carried 32 states and the District of Columbia. If you add up the 1994 votes for governor, senator and representatives in each of those 32 states, you find that 13 of Clinton's states would be in the Republican column and eight others too close to call. That yields an electoral vote count of Clinton, 81; undecided, 141; and Republican, 316.

This is obviously a theoretical exercise. White House officials point out that Clinton's approval rating in California and New York, the two largest states that this statistical model rates as tossups, is significantly higher than that of the Democratic gubernatorial candidates who lost Tuesday. But some larger truths about the electoral map can hardly be disputed:

* In 1992, Clinton carried five southern and border states with 47 electoral votes. At this point, only his home state of Arkansas can be counted clearly on his side. His exit poll score in Tennessee, home state of Vice President Gore, was 38 percent favorable and 57 percent unfavorable. Much of the South looks worse.

* In the key Clinton states of the Midwest -- including Illinois, Iowa, Michigan, Minnesota, Ohio and Wisconsin -- Republicans won all but one of the 10 gubernatorial and senatorial contests and in every state but Minnesota won the majority of the House vote as well. Clinton has his own problems. In Michigan, for example, his scores are 44 percent favorable, 51 percent unfavorable.

* Republicans won four of the six top races in Massachusetts, New York and Pennsylvania -- Northeast building blocks of any Democratic presidential victory. But in the first two, Clinton's approval scores still top his disapproval. New Jersey, the classic swing state in the region, reelected Sen. Frank R. Lautenberg (D), but Clinton has a four-point deficit in his approval score there.

* In California, the top prize in the West, Republicans kept the governorship, apparently lost their Senate bid and narrowly outpolled the Democrats in House voting. Clinton's scores are virtually even -- 48 percent approval, 47 percent disapproval -- a measure of how intense the struggle is likely to be for the giant prize of 54 electoral votes that went to the president last time.

Republicans could still make it easy for the president, by overreaching on their midterm mandate, quarreling among themselves or presenting an unattractive challenger in 1996. But the Democrats cannot count on that.

How Clinton starts the comeback battle is a matter under intense debate inside the White House. Conventional wisdom would have him move right -- or as some would put it, to the center -- to accommodate the public mood. In a speech on Thursday, Clinton acknowledged that Republicans had won a "smashing victory" with the message that "government is the enemy," and he pledged "to do more to limit government's reach into {people's} lives and to make more efficient the government they pay for."

But history suggests that any visible move to the right risks rebellion from the activist left of the Democratic Party, the forces that in 1968 backed Eugene McCarthy and then Robert F. Kennedy against Johnson and Hubert H. Humphrey -- the eventual nominee who lost to Richard M. Nixon -- and in 1980 supported Edward Kennedy against Carter.

Coelho said, "Any president who gets challenged for renomination is weaker as a result. I know they understand that at the White House. And I don't think the American people basically want him to change his stripes. ... He's a mixture of things. That's why he got elected and that's why he should stay what he is."

White House adviser George Stephanopoulos also maintained that there is no dilemma.

"The budget we passed reduced the deficit and it provided a tax cut for millions of working poor families," he said, presumably pleasing both budget-conscious Perot voters and core Democratic blue-collar constituencies. Stephanopoulos blamed the "problems in explaining what we'd done" for the failure to reap any political reward in Tuesday's voting for what he viewed as a policy triumph.

But the problems are not easily dismissed. A top Republican strategist suggested Thursday that welfare reform offers Clinton a perfect vehicle for repositioning himself to the right.

"The car is all warmed up and ready," he said. "All he has to do is slide into the driver's seat. He can say to the Republicans, 'I'm with you. Let's fix this welfare system now. You pass the bill and I'll sign it.' And he'd get all the credit, just like he did on NAFTA {the North American Free Trade Agreement}, which was passed with Republican votes."

But a welfare reform plan that would set a two-year deadline for benefits -- as proposed by Republicans and endorsed, with conditions, by Clinton -- is strenuously opposed by liberals in Congress, including the Congressional Black Caucus.

Were Clinton to do what the Republican strategist suggested, Jesse L. Jackson -- a threat to challenge Clinton in the Democratic primaries or as an independent -- would denounce the move. Already, his speeches condemn Clinton for supporting "three-strikes-and-out, two-years-and-off."

And the African American vote, the single most important ingredient in the Democratic base, no longer can be taken for granted. Exit polls showed Republican candidates known for conservative policies made serious inroads into the black vote on Tuesday: California Gov. Pete Wilson and Michigan Gov. John Engler each got 16 percent; Pennsylvania Gov.-elect Tom Ridge got 13 percent. More significantly, Sen. Daniel Patrick Moynihan (D-N.Y.), who was challenged by black activist Al Sharpton in the primary, lost 20 percent of the African American vote to Bernadette Castro (R), his unsuccessful opponent Tuesday.

Moreover, Republicans are adding steadily to their ranks of black elected officials, from Rep.-elect J.C. Watts in Oklahoma to Suffolk County (Boston) District Attorney-elect Ralph C. Martin II.

It's one more worry on a long list of Democratic headaches.