CHARLOTTE, N.C. - With the American labor movement newly energized by its most serious threat in years, the Democratic Party's decision to hold its 2012 convention in the least union-friendly state is causing friction with a key constituency.

The Democratic National Committee selected Charlotte to show confidence in the party's ability to win crucial swing states in the South, including North Carolina, that President Barack Obama carried in 2008. But the choice isn't sitting well with some union leaders.

"I think the Democratic Party is in crisis and they're trying to figure out who are they really going to represent," said Angaza Laughinghouse, president of the North Carolina Public Service Workers Union.

Workers around the nation have rallied in solidarity with union brethren fighting Republican efforts to curtail collective bargaining rights for public employees in Wisconsin and Ohio. But the issue is a moot point in North Carolina, one of two states where all public workers are prohibited by law from engaging in collective bargaining.

In many other ways, Charlotte makes perfect sense as the site of the convention. A bustling city of more than 700,000 with a popular Democratic mayor, the Queen City is both a center of the American banking industry and a symbol of the New South.

But it's in a state where just 3.2 percent of workers belong to a union, the lowest percentage in the country.

The choice of Charlotte isn't a major setback for unions, but it illustrates how the Democrats have distanced themselves from organized labor over the last several decades, according to Eve Weinbaum, director of the Labor Center at the University of Massachusetts in Amherst.

"The Democrats are following a strategy they've been pursuing for 20 years or more, in which they try to win over the swing voters while to some extent ignoring their base," she said.

Part of the Democratic establishment, though, has moved to back the protests of public sector unions, most notably the group Organizing for America, Obama's political arm within the Democratic National Committee. Obama himself has called the Wisconsin proposal "an assault on unions."

Top labor leaders in North Carolina and nationally have praised the decision to pick Charlotte, and party officials have cited that support to dismiss any suggestion that unions were snubbed.

"The DNC was pleased to have the support of North Carolina labor leaders, including the AFL-CIO, for Charlotte's bid for the convention," DNC spokeswoman Joanne Peters said. "The DNC has always been a strong supporter of workers and labor and, as always, will work with labor to stage the best convention we possibly can."

Still, Charlotte's labor force is overwhelmingly nonunion. That includes most of the people who will cater to the delegates, hotel and restaurant workers, and even those who will protect them, police officers and firefighters.

William Cashion, president of the Charlotte branch of the AFL-CIO, said he understands why the Democrats picked Charlotte.

"They can't win these states if you don't play there," he said.

But he also understands the unions' frustration. Union members usually supply the bulk of workers for Democratic conventions. "And that will be lacking here," he said.

But Cashion hopes the convention will highlight the labor movement's struggles in North Carolina and the South.

North Carolina has its share of labor history - the true story that inspired the Sally Field film "Norma Rae" happened in a North Carolina textile mill. But for decades, unions here - as in most of the South - have been largely irrelevant.

"You've got this combination of workers who are kind of ambivalent about unions in the first place, a history of violent repression and employers who are fiercely anti-union, and the result is an environment that is both culturally and legally hostile to the union movement," said Harry Watson, director of the Center for the Study of the American South at the University of North Carolina in Chapel Hill.

It wasn't until the 1970s that unions began major organizing drives in the South, but by then many traditional industries, like textiles, were in the early stages of a decline that saw them virtually wiped out by the dawn of the 21st century.

Labor leaders understand that Democrats aren't going to change the site of the convention, and hope the party will give them a chance to promote organized labor in a region that's long resisted it.

"There's a lot of work around conventions, and who does that work is going to be important," said Harris Raynor, the southern regional director for Workers United, an affiliate of the Service Employees International Union that represents about 5,000 North Carolina workers in jobs ranging from industrial laundries to food service. "We'll see. I've already been thinking about which of my members could benefit from this."

The choice of Charlotte could end up being a boon for unions, he said, if it provides a stage for organized labor to argue it makes businesses more successful.

"Given the debate going on in the country," he said, "unions have to do a much better job of showing how they add value."