Clinton Holding Significant Lead : Presidency: Despite tightening in popular-vote polls, he retains large margin in electoral votes. Bush still in uphill battle against persisting mood of discontent.

WASHINGTON —  This year’s bizarre three-way struggle for the White House is grinding to its climax Tuesday with Democratic nominee Bill Clinton clinging to a significant lead in electoral votes while President Bush strives to pull off an upset by overcoming the nation’s persisting mood of discontent.

Meanwhile, maverick Ross Perot, having apparently helped Bush narrow Clinton’s lead in the polls of late, seems headed toward the biggest share of the popular vote won by any third-party or independent candidate since 1968. But with Perot’s recent surge leveling off or declining in the polls, analysts suspect that the main impact of his candidacy may be to serve as a symbol of protest rather than influence the contest’s ultimate outcome.

In the battle between Clinton and Bush, Republican strategists point to the President’s gains in public opinion surveys and talk optimistically about his prospects of staging an upset so dramatic it would make Democrat Harry S. Truman’s stunning 1948 triumph pale by comparison.

“If you look at the national polls and look at the national trend line, we’ll pull into a tie on Monday and go ahead on Election Day,” Bush campaign pollster Fred Steeper predicted.

“I think it’s a 50-50 call who wins the election right now,” Bush senior adviser Charles Black told reporters Friday. “I’d rather be the person who has the momentum than the one losing voters.”

But Clinton’s partisans claim that Bush’s momentum has been halted, and perhaps reversed. As evidence, they cited a new poll published in the New York Times today that showed Clinton ahead of Bush by nine percentage points, 43% to 34%, with Perot at 15%. The survey, taken Tuesday through Friday, had a margin of error of plus or minus two percentage points.

A poll published by the newspaper a week ago today had put Clinton’s lead at five points.

Steeper said his last national poll, completed Friday, gave Clinton an advantage of “five or six points” over Bush.

Clinton aides said their polls on Friday put him ahead of the President by seven points.

Bush’s political position unquestionably has improved from a few weeks ago, when he trailed in most polls by double digits. But events late in the week may have toughened his bid to finally pull ahead of Clinton.

A federal grand jury investigating the Iran-Contra arms-for-hostages deal released a note on Friday written by former Defense Secretary Caspar W. Weinberger that cast doubt on Bush’s longstanding claim that he did not know the U.S. weapons sale to Iran in 1986 was intended as an inducement to gain the freedom of U.S. hostages.

And later in the day, federal regulators announced the closing of the First City Bank of Houston, on whose board Bush used to sit. Clinton partisans are hoping that the bank’s insolvency will remind voters in the President’s adopted home state of Texas of the weakness of the economy in general and problems plaguing the banking industry in particular.

But apart from these developments, it is mainly the harsh calculus of the Electoral College that argues against Bush’s chances. Indeed, role reversal has occurred in the 1992 campaign, with the President finding himself needing the type of last-minute surge that recent Democratic presidential candidates vainly hoped for as they sought the 270 electoral votes required to win the White House.

“Bush is in the position that Michael Dukakis was in 1988 and (Walter) Mondale was in 1984, of desperately seeking 270 electoral votes,” said Mickey Kantor, Clinton’s national campaign chairman.

A Republican win on Tuesday, conceded one GOP consultant who helped guide the President to victory in the 1988 campaign, would require a whole series of hard-to-control circumstances to go the President’s way and tip numerous states into his column. “All it takes is one sneeze or one hiccup and it can’t happen,” he said.

A Times state-by-state assessment outlines the advantage Clinton enjoys going into Election Day and the dimensions of the challenge confronting Bush.

Based on poll data, interviews with a range of political experts and past voting trends, Clinton is favored to win 18 states and the District of Columbia. That gives him 241 electoral votes, only 29 short of 270. Bush is favored in 14 states, with 137 electoral votes.

Another 18 states with 160 electoral votes are rated as tossups. Thus, to win the election, Bush must win 133 of those votes--meaning virtually every tossup state.

The graveness of the President’s predicament is underlined by his difficulties in the nation’s 10 most populous states. Three of these--California, without which no Republican has won the White House this century, New York, a traditional Democratic stronghold, and Illinois, bellwether of the Midwest, are generally conceded to be all but locked up for Clinton. Together, they account for 109 electoral votes.

Pennsylvania, with its 23 electoral votes, is viewed to be leaning to Clinton, although aides to Bush on Saturday said they believe that the race is tightening there. As a result, Bush tentatively plans a foray to Philadelphia on Monday.

Clinton’s advisers, taking no chances, dispatched him to the state Friday and scheduled two more visits by him before Election Day.

At a rally in Pittsburgh on Friday, Clinton could hardly be accused of over-confidence concerning the state. “I need Pennsylvania, I need western Pennsylvania, I need Pittsburgh,” he declared. “I can’t win without you.”

As for Bush, two of the top 10--Texas, with 32 electoral votes, and Florida, with 25, are counted as imperative for him to win. “I concede to you, if we lose Texas or Florida we’ll have a very tough time of winning,” senior Bush adviser Black said.

Florida now seems reasonably safe for the President; the Clinton campaign privately concedes it to him. Texas, however, remains surprisingly uncertain, GOP pollster Steeper said.

Although the expectation remains that Bush will carry it, native son Perot could siphon off enough votes from conservatives and moderates to give the state to Clinton. The Democrat is planning one more campaign visit to the state on Monday.

Of the four remaining top 10 states--Ohio, Michigan New Jersey and North Carolina--most analysts figure Bush needs to win at least three and possibly all four. Recent public and private polling suggests that will be no easy task.

His best chances are in Ohio, a Republican bastion which only two Democrats--Jimmy Carter in 1976 and Lyndon B. Johnson in 1964--have carried since Franklin D. Roosevelt’s 1936 landslide, and North Carolina, where Clinton is at a disadvantage because the black population is not as large as in most other Southern states.

In both states, Bush and Clinton are running about even in the polls.

But in normally Republican New Jersey, which gave Bush 57% of its vote in 1988, a poll released today by the Eagleton Institute of Rutgers University gives Clinton 45% of the vote, 37% for Bush and 17% for Perot. The survey of 580 likely voters has a margin of error of plus or minus 4%.

In Michigan, Republican hopes for a Bush win have been built around the charges that Clinton’s advocacy of tougher fuel efficiency standards would cost auto industry jobs. GOP strategists also have hoped Perot would attract discontented voters who might otherwise support Clinton.

But on Friday, a poll released by the Detroit News gave Clinton 43% of the vote to 33% for Bush and 17% for Perot. The survey, conducted Wednesday, had an error margin of plus-or-minus 4 points.

“Perot gave us a scare (in the state) last week, but it seems to have stabilized,” said Don Sweitzer, Clinton’s Michigan coordinator.

Times staff writers Douglas Jehl and David Lauter contributed to this story.

Down to the Wire

Based on polls and interviews with political experts, Bill Clinton remains close to the 270 electoral votes needed to claim victory. President Bush’s chances depend on his ability to claim nearly all of the remaining tossup states.

White: Solid / leaning Clinton (241) Arkansas: 6 Connecticut: 8 D.C.: 3 California: 54 Hawaii: 4 Illinois: 22 Maine: 4 Massachusetts: 12 Maryland: 10 Minnesota: 10 Missouri: 11 New York: 33 Oregon: 7 Pennsylvania: 23 Rhode Island: 4 Tennessee: 11 Vermont: 3 Washington: 11 West Virginia: 5 *

Black: Solid / leaning Bush (137) Alabama: 9 Alaska: 3 Florida: 25 Idaho: 4 Indiana: 12 Mississippi: 7 Nebraska: 5 North Dakota: 3 Oklahoma: 8 South Carolina: 8 Texas: 32 Virginia: 13 Utah: 5 Wyoming: 3 *

Gray: Tossups (160) Arizona: 8 Colorado: 8 Delaware: 3 Georgia: 13 Iowa: 7 Kansas: 6 Kentucky: 8 Louisiana: 9 Michigan: 18 Montana: 3 North Carolina: 14 Nevada: 4 New Hampshire: 4 New Jersey: 15 New Mexico: 5 Ohio: 21 South Dakota: 3 Wisconsin: 11 Sources: Public and private poll data, interviews with Republican, Democratic and independent political analysts, Congressional Quarterly.