With only one day to go before the election, the race for the presidency between Vice President Al Gore '69 and Texas Gov. George W. Bush will by decided by the outcome in 13 currently deadlocked swing states.

Most national polls give Bush a 3 to a 4 percentage point popular vote lead, but neither candidate has sewn up the 270 electoral college votes needed for victory.

According to the latest ABC News state-by-state analysis, Bush holds 25 states worth 213 electoral votes, while Gore leads in 12 states plus Washington, D.C. for 182 votes.

But 13 key states are still up for grabs--and the Gore campaign's internal polling shows they are only behind by 1 point nationwide and within the margin of error in enough battleground states to pull out the election.

The states, identified by ABC News, range from New England to the Sun Belt, and include 143 electoral votes--enough to put either candidate well over the top.

In the past few days, both candidates have traveled frenetically to and from the swing states--Wisconsin, Michigan, Florida, Pennsylvania, Oregon, Maine, Missouri, West Virginia, Tennessee, Arkansas, Iowa, Minnesota and New Mexico--in a last-minute effort to shore up traditional constituencies and appeal to undecided voters.

"Each campaign is striving to persuade undecided voters in the 13 or so states where the polls show an extremely tight race in which either candidate has a reasonable chance to prevail," said IBM Professor of Business and Government Roger B. Porter, an economic policy adviser in three Republican presidential administrations. "As a result, both candidates are attending rallies long into the night in these key states."

Gore campaigned in Pennsylvania, Michigan and Wisconsin yesterday, trying to rally traditional Democratic labor and black voting bases.

Bush, meanwhile, spent the day barnstorming across Florida, promoting his Social Security investment plan, saying that Gore was using "scare tactics" as he criticized Bush's tax cut plan.

With the race so tight, both parties have spent millions in extensive get-out-the-vote efforts that might be the deciding factor in some key swing states.

"It looks as if there are enough states where it's close enough so it's going to be a turnout election," said Kennedy School Lecturer in Public Policy Marty Linsky, adding that local races, ballot questions and the weather will all make a difference.

But despite the closest presidential race since 1960, most experts do not expect a high voter turnout tomorrow.

A lower turnout will favor Bush, according to Bradlee Professor of Government and the Press Thomas E. Patterson, because a disproportionate number of people who do not vote are low-income members of the Democratic base.

"The smaller and smaller the turnout gets, the more and more it works to the advantage of Republicans," Patterson said.

The campaign took a few unexpected turns on Thursday, when a Maine reporter broke the story that Bush had been arrested for driving under the influence in that state in 1976, and when Bush said that Democrats wanted to run Social Security "like it is some kind of federal program."

The DUI arrest is expected to have a negligible effect on the election, but Gore has used Bush's Social Security gaffe--which Bush aides have defended as being taken out of context--to question Bush's experience and credibility.

Both Gore and his running mate Sen. Joseph I. Lieberman (D-Conn.) have increasingly questioned Bush's leadership credentials in the closing weeks, especially on the airwaves. A new Gore television advertisement includes the non-discreet tag line: "Is he [Bush] ready to lead America?"

Bush spokesperson Ken Lisaius derided what he called the "bitter, divisive tone" of Gore's campaign.

"The whole theme of this last week has been bringing Americans together," Lisaius said. "It stands in stark contrast to the Gore campaign's final days of negative, attack-style politics. Our campaign continues to be positive, theirs continues to be negative. I don't think that's lost on anybody."

Gore deputy national spokesperson Devona Dolliole insisted Gore is running a positive campaign, however.

"We have focused on the issues since the beginning of this campaign, and we continue to focus on the issues now," Dolliole said.

Gore must also contend with another potential trouble spot--Green Party candidate Ralph Nader. Nader is running at 4 percent nationally, and could draw away enough liberal-minded voters from Gore to give Bush crucial victories in enough swing states to win the election.

"There's no question in my mind that he has captured the imagination and the emotions of a significant group of people," Linsky said. "In a very close election, that could make a real difference."

Still, Gore retains an edge with voters on most of the major issues--an advantage that experts said will propel him to victory, provided he gets people out to vote.

"He needs to drive home a couple of large issues," Patterson said. "If Gore can get people walking into the polling booth on Tuesday thinking issues and not personality, then he maximizes his chances."

Dolliole said Gore would emphasize in the next two days the "big choice" that voters face, asking whether they want to "squander the surplus" or protect Social Security and Medicare, and continue the prosperity of the past eight years.

Gore is expected to campaign in Iowa, Missouri, Michigan, Florida and Tennessee today and tomorrow, while Bush will hit Tennessee, Wisconsin, Iowa and Arkansas before returning to Texas.

Nearly as important as the outcome of the presidential race are the races to determine the balance of power in the House and Senate.

Seven Republican and two Democratic seats appear vulnerable in the Senate, where Republicans currently hold a 54-46 edge. In the House, where

Republicans hold a 222-209 advantage, only three to four dozen seats are clearly up for grabs.

Democratic party officials, however, are increasingly confident that they have a strong chance to win back the House, if not the Senate.

Symbolically, a groundswell of support has developed for former

Missouri Gov. Mel Carnahan--who died in a plane crash Oct. 16--in his race against Republican opponent Sen.

John Ashcroft.

Carnahan died too late for his name to be removed from the ballot, so his widow, Jean Carnahan, is running in his place. In polls taken this week, Carnahan was shown to be tied with or even leading Ashcroft.