Labor Day is the traditional end of summer. It is also the traditional day to comment on the decline of the labor movement, to which many of us owe a day off, if not much, much more.

It’s true that trends don’t look good for organized labor. Union membership has declined steadily since the late 1960s, falling from about a third of the workforce to slightly more than 10 percent. Globalization and technology have disrupted the industries that were most heavily unionized. And during the financial crisis, unions, particularly those in the public sector, have become scapegoats for opportunistic politicians, who push “right-to-work” legislation that would weaken unions and give them less clout at the bargaining table.

But not all the news on the union front is bad. Companies in distressed industries have found unions like the United Steelworkers to be constructive partners in restructuring to meet the challenges of the new economy. And organizing successes among workers at the low end of the wage scale, including retail, domestic and restaurant workers, point to a better future for people who work hard and have little to show for it.

As a nation we should see these developments as positive, whether individually we belong to a union or not. The rise of the labor movement coincides neatly with the creation of the American middle class, one of the greatest economic engines the world has ever seen. The decline of union membership also coincides with the middle class’ shrinking share of the national economy. It was irresponsible investors, not powerful unions, that brought down the economy. Weakening unions won’t help build it back.

The last 40 years have been bad for many of the institutions that once provided structure to communities, including churches, political parties, schools and universities — even newspapers. They have all struggled to make themselves relevant to new realities and unions are no different.

But we are rooting for their success because unions have a lot to offer in building a stronger middle class and a stronger country.

Unions are not at odds with companies that want to respond quickly to market conditions.

Unions can provide training, administer health plans and pensions, supporting the creation of a flexible workforce that can move easily between employers with less administrative hassle. Companies benefit from having access to those workers, and the workers and their families would benefit from secure employment. This is what builds strong neighborhoods and communities.

Unions also give voice to the concerns of people who would otherwise be left out of the political debate. Much is made of the influence of political donations by unions, but that charge conveniently ignores the growing power of corporate money in our system. Democrats and Republicans both rely on Wall Street to fund their campaigns, and workers would be silenced if they did not combine resources and speak with one voice.

Our society is built on a system of checks and balances. Strong unions are one of the things we need for it to work.

So, if you have the day off, thank a union member. And wish them a good year, for all of our sakes.