NEW YORK -- Labor Day, its significance often lost in the haze of our collective national barbecue, is supposed to be an occasion for organized labor to celebrate itself.
But as this year's holiday neared, talk in labor circles has been the mostly bitter, confrontational vocabulary of strike threats.
The latest came Friday from Midwest Express flight attendants, who pledged a mass walkout or sporadic stoppages after contract negotiations with the airline broke down.
Boeing machinists appeared close to striking, but heeded a call for time from mediators, after the company made what it insisted was its last, best contract offer. Workers at 29 major ports along the West Coast may soon be walking out.
And of course, there are Major League Baseball players, whose final-hours agreement Friday with team owners averted a strike whose prospect has shadowed the game for months.
The coincidence of so many near-strikes might be enough to suggest that organized labor is reasserting itself in a down economy, a response to demands for belt-tightening and givebacks by employers.
Labor experts do see common concerns among workers in several of the recent faceoffs, but they call the spate of recent walkout threats anomalies. Most big unions, they say, have still all but forgotten how to strike.
In the Boeing, baseball and port labor disputes, "you have very strong unions in a situation where the employers were and are looking for very significant changes from the bargaining units," said Peter Olney, associate director of the Institute for Labor and Employment at the University of California at Berkeley.
Those situations, though, are atypical.
"I wish it was a sign of the times," Olney said of the recent surge in strike threats. "I think we'd have a far healthier labor movement if it was."
In the early 1950s, when organized labor was at its peak, strikes were frequent, and potent. There were a record 470 strikes involving more than 1,000 workers in 1952.
These days, the records being set are at the other end of the scale. Last year, there were just 29 strikes involving more than 1,000 workers, the second lowest ever. The numbers of work days lost to strikes and lockouts reached historic lows, according to government's Bureau of Labor Statistics.
In 1950, about a third of all workers were union members. Now, that figure is about 13.5 percent. With government workers out of the equation, union membership in private industry is now less than 10 percent.
The dropoff in union membership and strike activity is partly a symptom of dramatic contraction in industries like domestic steel, rubber and autos, all labor strongholds. In the 1970s and 1980s, employers grew far more aggressive in hiring replacement workers during strikes and resisting unionization. Unions, on the defensive after setbacks like President Ronald Reagan's decision to hire replacements for striking air traffic controllers in the early 1980s, became leery of the strike, experts say.
That backslide stabilized during the 1990s. Union membership roles are no longer dwindling. Labor won some big victories, successfully striking United Parcel Service and negotiating for more generous benefits with automakers when times were good.
The recent bout of strike talk is a sign of the harder line that big labor has taken in the past few years, said Alexander Colvin, an assistance professor of labor studies and industrial relations at Pennsylvania State University.
"In these kinds of economic times, there's more focus (by unions) on trying to defend some of the benefits they've won in better times," Colvin said.
But even as the economy threatens some of what they've won, just the fact that a handful of unions are talking strikes and wield the power to make them work should give the labor movement something to celebrate, he said.
"Its' more hopeful than it was 10 years ago, even though they're facing these challenges right now," Colvin said. "It's very different to be facing a challenge when you feel you have some energy and the strategies needed to respond."