LAS VEGAS (Reuters) - President Barack Obama made history in his 2008 election victory as the first black U.S. president, but he risks achieving another, less welcome, first if he wins again in November.
Obama is on course to become the candidate with the lowest support from white male working class voters to win a U.S. election if he triumphs over Republican Mitt Romney on November 6.
Polls show support for Obama from white males without college degrees at under 30 percent, well below the 39 percent he had when he defeated Republican John McCain four years ago. While he has overwhelming support from Hispanics and blacks and does well among women, the Democratic president needs to shore up his backing among those men.
Richard Trumka, the most powerful U.S. union leader and an important bridge between the White House and blue-collar America, sees two solutions to Obama's problems: mount labor's largest voter outreach effort ever, and keep up the attacks on Romney's business record.
"We're absolutely going to do good work on the ground, mobilizing workers. We will have 400,000 volunteers this cycle," Trumka, a former coal miner who is president of the 12-million-member AFL-CIO, the largest U.S. labor federation, told Reuters.
"We'll be involved in 32 battleground states, up and down the ballot from Barack Obama, the House races, the Senate races, the state house and senate races," he said.
The union's main focus will be six states - Pennsylvania, Ohio, Nevada, Wisconsin, Michigan and Florida - where polls show the presidential race is close. In the 2008 election, more than 250,000 union volunteers took to the streets.
Trumka said constant ads and speeches by Obama's campaign targeting former executive Romney's business record and refusal to release more than two years of tax returns should win over more working-class men.
"A lot of arguments are going to resonate with our members," Trumka said in an interview during a trip to Las Vegas to speak at union conventions. "Outsourcing because they know that he was the leader, his firms were the leader, in outsourcing. That will have a big, big jog."
And he said blue-collar workers, who are fighting for their jobs and benefits in a difficult economy, will be outraged over Romney's refusal to release more tax returns.
The AFL-CIO does not break down its membership by race, but the majority of its members are white and more men belong to unions than women.
"The fact that he has offshore secret bank accounts will fly with our members, because they'll assume that he's taking advantage of those tax loopholes and doing it offshore and that's why he won't give the tax returns," Trumka said.
Unions, already battling Republican state governments trying to curtail their negotiating rights, are throwing everything they can at the 2012 election.
Thanks to the U.S. Supreme Court's Citizens United decision that lifted many campaign restrictions, union organizers this year can spend union funds to try to politically influence the general public. Worker's Voices, the AFL-CIO's Super PAC, will take advantage of the ruling to send volunteers to knock on doors, urging votes for Obama.
"Will we get every one of them? No. But will we make a difference in our areas? Yes, we will. Voting for their own economic interests generally trumps any kind of clichés, hidden agendas or anything else. They vote in their own economic interest," Trumka said.
A Reuters/Ipsos poll last week showed that constant criticism by the Obama campaign and its allies of Romney's business tenure and personal finances may be harming the Republican's ratings.
More than one-third of registered voters said that what they had heard about Romney's taxes and his time at Bain Capital, which critics say was responsible for sending a number of U.S. jobs overseas, had given them a less favorable impression of him.
But the former Massachusetts governor has a huge lead with non-college-educated males in other polls.
Romney regularly bashes "union bosses" as he campaigns and he also has been hammered by Democrats for opposing Obama's rescue of the U.S. auto industry.
"There's no reason that there should be a white male, or a white, voter gap," said Trumka, who called the auto rescue "a magnificent thing."
A Washington Post survey last month showed Romney ahead by 65-28 percent among male voters who had not attended college, while a Quinnipiac University poll had him leading with 56 percent and the Democrat with 29 percent of that group, down from 32 percent earlier this year.
That compares to the 39 percent that Obama won in 2008. High unemployment now harms Obama with whites in Rust Belt states, but even in his historic election victory four years ago non-college-educated white men were Obama's weakest demographic.
He is not alone among Democrats in struggling with what used to be some of the party's core voters. But with white male voters' share of the electorate dropping, Obama can still win the election if his numbers rise in that group even by a relatively small amount.
"Obama doesn't need to carry the white working class vote, but he doesn't want to lose it overwhelmingly," said Herb Asher, a political scientist at Ohio State University. "If you have a close election, and it makes a small difference, that's the difference between defeat and victory.".
Republicans have triumphed among white working class males for more than three decades, partly by making the most of cultural differences with Democrats on issues like abortion rights, gun control and affirmative action.
But Romney has had his own troubles with working class male voters. He routinely lost them during the primaries, as his fellow Republicans accused him of being a "vulture capitalist."
A Gallup poll this month found that one in five voters - including one in five independents - was less likely to vote for Romney because of his wealth. And the Obama campaign has stressed the Democrat's bailout of U.S. automobile makers, which they said saved thousands of jobs.
Doug Ripple, 45, an Insulators' union member from Dayton, Ohio, said he knew people who had doubts about Obama, after years of struggling in the weak economy. But he said Romney seemed too much in favor of the rich to win his vote. "Obama's for the working class. We're not billionaires."
A quarter of AFL-CIO members did not vote for Obama in 2008.
"Some of this I think was pure racism," said Trumka. "Some of them would be gun owners, some of them would be right-wing. Some of them would be ... dyed-in-the-wool Republicans."
Democrats acknowledge that Obama is unlikely to capture the white male vote, but say he can be re-elected if he minimizes the damage because of his huge edge with black and Hispanic voters.
In 2008, whites accounted for about three-quarters of U.S. voters, blacks represented about 12 percent, Hispanics about 7.5 percent and Asians 2.5 percent. The percentage of minority voters is expected to be greater this year.
Obama easily won the White House in 2008 despite his relatively weak support from whites. But his campaign is trying to keep him from slipping more with white working class voters by persistently depicting Romney as an out of touch elitist.
"What you do is, you make Romney a space alien," said Jeremy Mayer of George Mason University in Virginia, by defining him as a man who outsources jobs to China and hides his money overseas.
"If you can make Romney look like the guy who is firing the white working class, then you can stop the bleeding," he said.
(Editing By Alistair Bell and Vicki Allen)
This story was corrected to fix the spelling of Mayer in the penultimate paragraph