It's one of the few things that can bring almost all of the state's politicians together: Keeping South Carolina a right-to-work state.

So it shouldn't have been a big surprise to see Charleston Mayor Joe Riley, a lifelong Democrat, standing next to most of the state's highest-profile Republicans, including U.S. Sen. Lindsey Graham, Gov. Nikki Haley and U.S. Rep. Tim Scott, to decry the National Labor Relation Board's lawsuit against Boeing.

Charleston County Council Chairman Teddie Pryor, a Democrat, nodded along in the audience. North Charleston Mayor Keith Summey, a Republican, apologized to the company's local employees, decrying the federal suit as "ludicrous."

Haley and Scott said the state's right-to-work status is very important to the state's efforts to recruit new business, a major political priority at the moment, given the state's high unemployment rate.

The state's animosity toward unions dates back at least to the aftermath of the Civil War, said Hoyt Wheeler, a retired professor of labor relations in Columbia and a labor arbitrator for 35 years.

"The textile industry was attracted here from New England by offering cheap, docile, nonunion labor, and it worked," he said.

Wheeler said the anti-union sentiment continues to be driven by the notion that it helps the state's economic development, as well as giving management a freer hand.

"It's clearly in the interest of the people who have the power and the money in this state to keep unions out," he said. "They're able to make more money, and there's a strong inclination to crush mercilessly any hint of anyone suggesting this is not a good thing."

Haley was sued this year in U.S. District Court after vowing that the state would try to keep unions out of the Boeing Co. plant in North Charleston. The International Association of Machinists and Aerospace Workers and the AFL-CIO asked for a court order telling Haley and her director of labor to remain neutral in matters concerning union activities.

"There's no secret I don't like the unions," Haley said at the time. "We are a right-to-work state. I will do everything I can to defend the fact we are a right-to-work state. We are pro-business by nature. I want us to continue to be pro-business. If they don't like what I said, I'm sorry, that's how I feel."

South Carolina is not only a right-to-work state -- which means an employer and a union cannot require workers to either join a union or pay union dues as a condition of employment -- but it also ranks near the bottom when it comes to the percentage of its employees in unions.

Fewer than one in 20 South Carolina workers are union members, and only North Carolina, Arkansas, Mississippi, Georgia and Louisiana and have lower percentages, according to the AFL-CIO.

U.S. Sen. Jim DeMint, R-S.C., did not attend Thursday's gathering, but later said he was there in spirit.

"The point we want to make to the media and folks all over the country is this is just not about Boeing or South Carolina," he said later. "This is a direct political assault on right-to-work states. ... It's one of the worst cases of administration thuggery that I could imagine."

The elected officials acknowledged that they could do little directly to stop the board, though Graham and Scott mentioned trying to de-fund the board, an option Scott described as a long shot.

S.C. Speaker of the House Bobby Harrell said the General Assembly could pass resolutions against the move.

DeMint agreed that there's little Congress can do to stop the board. "Sunlight is the best disinfectant, and the best thing we can do now is let Americans know that here's yet another example where the administration is harassing American citizens, American employers, costing us jobs and costing us money," he said.

Wheeler said he had not formed an opinion about the board's action against Boeing, but he said he wasn't surprised that South Carolina politicians are reacting "in horror."

"Striking is a protected activity. It's part of the system that we have in this country," Wheeler said. "That legal right to strike is something that's supposed to be protected."

The state's hostility to unions was clear long before the most recent Boeing dust-up. In November, 86 percent of state voters approved a constitutional amendment designed to ensure that union elections remain done only by secret ballot here.

The vote came as Congress considered expanding the ability of unions to form via "card checks," or requiring employers to recognize a union if a majority of workers sign cards that support unionizing.

The NLRB has said it might sue South Carolina and three other states over such constitutional amendments.