A popular opinion holds that if only America had more factories, we'd be a much better country. But that opinion relies on a badly outdated stereotype of manufacturing and of the economy overall.
The fact is that Rust Belt cities have evolved. They are no longer dominated by "smokestack industries" belching pollution into the air. Yes, there are still factories -- but the smartest communities have evolved and adapted so that they are more diversified and less dependent upon churning out raw goods.
Take a look at the skyline of Pittsburgh, which was America's most prominent steel town:
What you see in Pittsburgh today, yes, still includes heavy manufacturing. But it also incorporates lots of other things, including a vibrant financial sector, cutting-edge computer and tech companies, and high-value manufacturing.
High-value manufacturing is good to have as part of a local economy. But high-value manufacturing is (generally) much more a process of taking lots of components and turning them into sophisticated equipment than it is about churning out lots of commoditized goods from raw materials. And if you don't understand the difference, you can't get economic policy right. High-value manufacturing usually involves complex assembly, computer programming, and highly-skilled finish work, not big smokestacks and long assembly lines full of people doing the same mind-numbing turn of the wrench over and over.
America produces more value in manufacturing than ever before. We just happen to do it with a lot fewer people -- because the people doing the work are producing much more value per person. That's good for all of us. What isn't good for us is to fall into outdated stereotypes about manufacturing "greatness" means.