"Union." Not as in "federal government," but as in "organization dedicated to protecting the rights of workers." The only reference to unions was when Obama mentioned Master Lock's "unionized" plant in Milwaukee as an example of jobs that can be brought home from overseas. It was entirely incidental.
I mention this because Obama early in his speech talked about how his grandparents, after World War II,
shared the optimism of a nation that had triumphed over a depression and fascism. They understood they were part of something larger; that they were contributing to a story of success that every American had a chance to share –the basic American promise that if you worked hard, you could do well enough to raise a family, own a home, send your kids to college, and put a little away for retirement.
The defining issue of our time is how to keep that promise alive. No challenge is more urgent. No debate is more important.
This is an elliptical reference to the fact that for three decades after the war productivity increases were passed through to workers. That didn't happen because bosses were nicer then. It happened because labor unions were powerful then. It doesn't happen anymore, and a big part of the reason why is that private-sector labor unions aren't powerful anymore.