Re: Damn.
"If you were completely convinced that the US economy is going down the drain, and the only way to stop it would be to bring some self-sufficiency back, how would you bootstrap manufacturing in the united states again?"
Step 1: Focus on what, specifically, you need to be able to make there. Don't try to make everything. If you try to make everything, you're going to run out of ways to promote that capacity before you've gotten far enough. It's also a bad idea Because there are plenty of reasons why other. countries might be better at making something. Unless you need it, the place that makes it is an enemy, or there's some reason to think that you could do a lot better at it than you are right now, it might be better just to let it happen where it's already happening.
Step 2: Figure out who does make those things. Are they your friends or your enemies? Study them and figure out why they can do it there and can't where you are. The process forks after this depending on your answer, but to avoid writing too much...
Step 3: Get more of whatever they have access to and you don't. If you don't have enough skilled people, figure out how to encourage education of more. If they don't have a regulation you have that slows them down, consider whether the regulation is necessary (don't just eliminate it, consider it). If they have particularly rare people, figure out how to convince some to move to you.
Step 4: Determine whether any of those differences are unfair. If they are breaking an actual law, one that's been written down and you can point to and prove they broke in a court that doesn't already agree with you, pursue that. If it's an international trade regulation, there is the WTO to handle that, well there would be if the US hadn't been blocking it for several years, but it can do some things. Here's where you might use some tariffs, as punishments for specific and real problems.
Step 5: If the rest wasn't enough, here's where you have to hand out cash. Private companies won't do something if it's not profitable. Creating an environment may not be enough in those cases. You may need to pay them to start. After a while, it becomes expensive to move what they started, and if you were successful with the environment thing, they won't need your help anymore, so those subsidies can be temporary. Tariffs to block all the competition as an alternative to subsidies usually won't work, but they especially won't work if the environment problems are still there. Even if the environment is good enough, tariffs will make it difficult for anyone to start if they import anything. A car company could have access to people trained in engineering, a place to build factories, and regulations making it easy for them to make and sell cars. If they don't have any of the materials with which to make cars because there is a tariff on those, they still won't build that factory. This is why step 1 is so important; unless you already make a bunch of steel locally, tariffs on steel and on cars is likely to prevent you from starting a car factory.
Governments aren't great at following this process. The current attempt is worse than usual at it.