Georgiana Dubin, 87, came to Mexico from Missouri in 1936 but says she has never voted in a U.S. election. The former dancer attended a luncheon last week hosted by Diana Kerry, sister of the presumptive Democratic presidential nominee, Sen. John F. Kerry of Massachusetts, and filled out a registration form to cast the first ballot of her life.

"I've been living here all these years, and I just realized that every vote counts," she said.

The votes of U.S. citizens living abroad are being courted by the Democratic and Republican parties more aggressively than in any previous election, officials from both parties said. They said the narrow outcome of the 2000 election, which George W. Bush won with a 537-vote margin in Florida over Democrat Al Gore, has motivated them to register every voter possible, including the millions of citizens who live abroad and are often overlooked.

Sharon Manitta, a spokeswoman for Democrats Abroad, who lives in Salisbury, England, said her group had chapters in fewer than 30 countries for the 2000 election but has them in more than 70 countries now. She said one chapter, Donkeys in the Desert, was opened in Iraq by employees of the recently disbanded Coalition Provisional Authority.

"It's just been incredible, just remarkable," said Manitta, who added that four months before the election, her group has already registered more than 8,000 voters in Britain.

Republicans are also meeting with expatriates. California Gov. Arnold Schwarzenegger has met with Americans in Israel, and former vice president Dan Quayle has visited Germany. Ryan King, deputy director of Republicans Abroad in Washington, said the son of Florida Gov. Jeb Bush, George P. Bush, would travel to France, Germany and Switzerland in September to drum up votes, and hopes to visit Mexico.

"People are motivated," King said. "You have people literally coming out of the woodwork to register. This is a very contentious, personal election. People really feel that it's going to affect them personally." He said Republicans were also planning advertising blitzes in foreign newspapers this summer and fall to register more voters.

Officials at the Federal Voting Assistance Program, the government agency that handles overseas voting, said that in 2000 they had 250,000 requests for voter registration applications from U.S. citizens living abroad. This year, as of earlier this month, they had sent out 340,000, and they expect to mail many more before the November election.

U.S. citizens living abroad must fill out a Federal Post Card Application for an absentee ballot and mail it to election officials in the U.S. city, town or county where they last voted or lived. Officials there then mail the voter an absentee ballot.

While there is no accurate census of how many Americans abroad are eligible to vote, one of the largest groups is U.S. military personnel and their dependents older than 18. The Defense Department says about 500,000 such people live overseas.

There are no firm statistics on the number of U.S. citizens who live abroad, with estimates from various government and private groups ranging from 3 million to 10 million. U.S. officials are attempting to count Americans in Mexico and several other countries, with great difficulty. It is widely believed that Mexico is the country with the largest population of expatriate Americans -- the embassy here estimates the number at 350,000, but others say it could be a million or more.

American cafes and English-language bookshops overseas are also functioning as voter registration centers. Democrats and Republicans interviewed abroad said they were more motivated this year not only because of the closeness of the last presidential race, but because many hold strong opinions about the Iraq war and see Kerry and Bush as offering dramatically differing visions of the future.

"It's at fever pitch," said Connie Helque, of the Association of Americans Resident Overseas in Paris. She said one man walked into the group's office and asked for 40 registration cards, saying he was going to get all his friends registered. "There's much more interest in this election," she said. "People are coming in who haven't voted in decades."

Americans abroad "are the 51st state," said Kelly Johnson, business manager of the Expat Survival Guide, a publication for Americans abroad based in Amsterdam. Johnson said she and other Americans were holding "vote-o-ramas" in the Netherlands, featuring live entertainment.

Much of the voter registration drive is being conducted on the Internet. In addition to the official site of the Federal Voting Assistance Program (www.fvap.gov), several new sites have been established to assist voter registration, including TellAnAmericanToVote.com, a nonpartisan site set up by several Americans living in Amsterdam and their Dutch friends.

"Americans living abroad don't vote," said Robert Checkoway, a Boston native and co-founder of the Web site, who hopes to change that. Interviewed by telephone from an Amsterdam bookshop where he was helping to register votes last week, Checkoway said about 3,000 people had downloaded voter registration forms from the Web site.

In Mexico last Thursday, Diana Kerry spoke at an event attended by about 100 U.S. citizens, most of whom were registering to cast absentee votes for the first time. Kerry, a schoolteacher who has taught in Europe, the Middle East and Asia, said she had been "beating the Bushes for Americans" in her recent appearances in Scotland, France, Germany, Austria, Ireland and Canada.

"The energy is huge," Kerry said in an interview. "Everywhere I go, people say, 'I have to vote this time. How do I do it? What can I do?' "

Susannah Glusker, of Democrats Abroad, said that as of Thursday, before the lunch with Kerry, about 500 U.S. citizens in Mexico City had registered to vote, five times more than in any other year she could remember.

Among those who turned out to see Kerry was Joe Nash, 92, who has lived in Mexico for half a century and helped found Democrats Abroad here to push the candidacy of Adlai Stevenson in 1952. "Definitely, there will be more voting from abroad this time," he said. "What happened in Florida was sickening."

Larry Rubin, a Republican activist in Mexico City, said he was confident that larger numbers of American voters abroad would favor his party. He said many U.S. expatriates tend to be business leaders and Republicans.

Republican efforts to turn out the vote here were "just gaining momentum," Rubin added.

American expatriate David Deverich, right, is assisted by Gabby Flavin of Democrats Abroad at a voter recruiting booth in Sydney earlier this month. With as many as 100,000 U.S. citizens in Australia, a push is on to register absentee voters for the November election. Diana Kerry, left, Sen. John F. Kerry's sister, speaks to supporter Joe Nash, right, at a campaign and voter registration rally in Mexico City last week.