Richard Yeselson mourns it:
The problem isn’t that most people hate unions. The problem for unions is that most people don’t care about them, or think about them, at all. … Sixty years ago, the UAW or the Mineworkers or the Steelworkers, not only deeply affected crucial sectors of an industrial economy, they also demanded respect from broader society—demands made manifest in the "political strikes" they organized, whether legally or not, to protest the issues of the day. Millions supported these strikes, millions despised them—but nobody could ignore them.
Felix Salmon wonders if unions will ever regain their footing:
One of the biggest secular forces in the decline of labor has surely been the glut of skilled and unskilled workers coming onto the international labor force in recent decades, particularly in China. As a result, I suspect that any truly important next-generation social movement will be profoundly international in nature, and will have to make big strides in China before it has any real effect in the US. Laborers in Chinese factories aren’t just competing with US workers for jobs: they’re also, in a weird way, the best hope those US workers have for real improvements in how they’re treated and paid.
Will Wilkinson makes a distinction between public sector unions (which he opposes) and private sector unions (which he supports):
Competitive globalized markets for labor and capital make the worst excesses of unions infeasible. That outsourcing and capital flight would prevent a reinvigorated American private-sector labor movement from becoming as a powerful force for a more social-democratic politics is a fact progressives have a hard time accepting, but for me that fact is more feature than bug. … It's pretty clear that global market forces function worldwide to keep unions' worst anti-competitive instincts in check.
(Chart from Mark Perry)