MIAMI (AP) - On a muggy afternoon, more than 3,000 immigrants, most of them Hispanic, wave flags, cheer and weep as they swear to protect and defend the United States of America as its newest citizens.
Moments later, dozens of volunteers from the Democratic and Republican parties swoop down on the new citizens as they file out of their citizenship ceremony in a Miami auditorium, competing to sign them up to vote. It's a scene that is being played out nationwide.
Supporters of Barack Obama and John McCain are fighting for every voter this campaign, and naturalized citizens of Hispanic descent are a growing target. In 2004, there were 4 million foreign-born Hispanics citizens of voting age. Today, that number is more than 5 million, according to an analysis of U.S. Census data by the nonprofit Pew Hispanic Center.
These new voters are especially important in swing states like Florida and New Mexico, said Jeffrey Passel, the center's senior demographer.
"In places where the election is very close, they make all the difference in the world," Passel said.
Voter registration data, polls and Associated Press interviews with new citizens in a half-dozen key states suggest Obama has the most to gain by reaching out to these new citizens.
Cuban-born Victor Castillo, 27, who took the citizenship oath along with his mother at the recent Miami ceremony, fought past a frenzy of party volunteers to register to vote with nonpartisan county poll workers, but said he was leaning toward Obama.
"Who's more willing to work with the middle class, not just the upper class? I believe Obama will be better for that," Castillo said, adding that he disliked McCain's negative campaigning. "He's trying to bring Obama down. Why don't you do something yourself, show your ability?"
Obama campaign spokesman Federico de Jesus said the Democratic presidential candidate is devoting more money to bilingual advertising than any previous campaign, and spending roughly $20 million on Hispanic outreach, including voter registration efforts.
"In the states where the difference is 1 or 2 percentage points, the ground operation is going to make the difference," he said.
Ana Navarro, McCain's adviser on Hispanic affairs, said Republicans aren't investing the same amount of money as Democrats on registering new citizens. She also allows that the party lost support among new Hispanic citizens because of some Republican lawmakers' remarks during the recent congressional debate over proposed immigration reforms.
But the McCain campaign is using Spanish-language ads to convince Hispanics that he was on their side of that fight and that he has had a lifelong interest in Latin America, Navarro said.
"On the other side, you've got a man who's never so much as set foot in Tijuana," she said.
Overall, the Hispanic vote seems to be coalescing behind the Democrats.
Hispanic registered voters supported Obama over McCain by a 66 percent to 23 percent margin in a nationwide survey conducted by the Pew center in June and July. The survey found that Latino voters have moved sharply into the Democratic camp in the past two years, reversing gains made by the GOP earlier in the decade.
In Florida, a state known for its conservative Cuban-American Republicans, this year marked the first time that more Hispanics are registered as Democrats than Republicans. At least part of that comes from new citizens. Still, recent polls show McCain ahead among Florida Hispanics overall, making support from new Hispanic citizens in the Sunshine State all the more crucial for Obama.
After the Miami citizenship ceremony, Panama native Graciela Hidalgo stood with her 11 year-old son Jesse waiting to sign up with the Democrats. Hildalgo, 46, has lived in the United States nearly half her life but waited to become a citizen, first because she had arrived illegally and later because she was too busy working and raising her son.
She said she was most worried about the economy, the Iraq war and, to a lesser extent, immigration.
"I would have liked Hillary," Hidalgo said wistfully of Hillary Rodham Clinton, "but McCain for me is not an option. He's all war, war, and the Republicans haven't done much."
Those new Florida citizens interviewed who did support McCain tended to be older and to come from communist Cuba or socialist-leaning Nicaragua and Venezuela, where their experiences made them more sympathetic to the Republican candidate, a former Vietnam prisoner of war.
Jose Delgado, 74, a retired construction worker, arrived in the United States in 1986 from Camaguey, Cuba, after years of struggling under the government there.
"McCain will be stronger on communism and in foreign affairs in general," Delgado said. "I'm not in agreement with many of Bush's policies, but (McCain) will bring change."
Strong sentiment for Obama emerged in interviews with new Latino citizens in other swing states with sizable Hispanic populations, although many also expressed admiration for McCain.
In Denver, Guatemalan native Eddie Samaoya, 73, who works as a press operator, says he and his six sons - all citizens- often chat about politics.
He believes both candidates could do a good job, but two issues are key: "McCain is capable, but Obama has a longer life ahead of him. And he can end the war," Samaoya said.
Mayra Crum, who came to the United States from Baja California, Mexico, registered as a Republican minutes after becoming a citizen at a Las Vegas ceremony and will vote for McCain. She thinks he can get the country out of Iraq and do more to help the "terrible" economy.
"He (McCain) has plenty of experience. You know, I love when he speaks - he makes you feel confident, like you're going to put your country in good hands," said Crum, 46, who teaches citizenship courses.
Even swing states with small Hispanic populations, like Virginia, could feel the effect of new Latino voters. Hispanics make up only about 3 percent of Virginia voters, but in 2006, Democrat Jim Webb won his U.S. Senate seat by a margin of only about 10,000 votes.
Salvadoran native Arturo Munoz, 64, of Fairfax, Va., began educating other Hispanic immigrants about the issues after his hours were cut at an aircraft maintenance company in March. Munoz, who supports Obama, became a citizen in August after living seven years in the United States.