I'd also add that one of the big weaknesses in the labor union model of doing things generally is that they're too tied to current employers/industries/categories of jobs and thus tend to be reactive rather than proactive.

As the economy shifted away from a manufacturing base, unions of manufacturing workers lost a lot of mojo.

Who are the real heavyweights in labor today? Those whose members are services workers--government workers, home health aids, teachers, etc.

Of course, the rise of temp agencies and designating workers as 'contractors' played a role in this.