Well, if a person was to actually limit their purchases to only products made in the U.S., I wonder what that would leave available...
So little seems to be made here anymore, and as you point out, it's declining rapidly. If all Americans would "buy into" buying only American, it might very well support a reasonable manufacturing base here, but short of massive support--it won't work. As you point out too, we would all be looking at considerably higher prices--and, alas, a very large number of Americans aren't making it right now, despite the relatively cheap goods. Those higher prices would end up raising the costs to businesses in the U.S. as well, and that would result in further price increases and effectively eliminate our already modest export industry--though our 'trade deficit' would be affected both positively and negatively. As buy American became ubiquitous, we'd obviously import less and less until it would consist of little more than raw materials we happen to need. Of course, that all means that we'd have very little trade with the rest of the world--and we do "enjoy" using the lure of access to American markets as a diplomatic tool and a form of international influence. There's something to be said for that as it's been useful. While in some way it might not be to our advantage to worry about other nation's economies, the influx of U.S. dollars into many other countries has helped substantially to grow their economies and improve the lives of their citizens. It's also simultaneously served to export more than a little "American culture", including "Democracy" and/or human rights and environmental laws. Of course, that's been far from perfect or conclusive, but it has resulted in some positive or desirable outcomes.
It seems to me it's a complex issue, and it would require considerable input from experts in economics, foreign relations, government and who knows what in order to even make an educated guess what effects such an economic policy would produce. Alas, though, even if everyone could afford it and it was determined that the good it produces here offsets any harm and further, at least considers the effect on the rest of the world... I just don't see Americans, in any large number, organizing, agreeing and comitting to such a plan, and it seems to me it would involve a pretty significant comittment (and one that might not even provide benefits in a "fair" manner). I must admit, while I might be willing to consider such a thing when there are competing American products which are reasonably competitive and it doesn't appear that the corporations involved aren't going to export their manufacturing capacity regardless of whether or not their North American arrangement is already profitable. Many companies have exported their manufacturing despite the fact that they were in fact profitable already--in favor of even more profits... and if they don't see a highly likely reduction due to 'buy U.S.', they'll just do it anyway. A laudable goal, though, to stop all this foreign outsourcing... Just seems unlikely to occur, at least not until things have gotten so bad that it's already too late.
I do hope there are some good answers--this or some other--that we can all get behind (and that we all get to hear about from our "leaders"), but so long as we rely on free (semi-free)/capitalism markets on a global basis, there's going to be a continued shift until wages are much more uniform across the globe. Countries that have more or better resources, including human (skills/education/health/age), raw materials, transportation, weather and more, will end up with many of the more desirable jobs (though wages will likely not be what they once might have been). The real answer to everyone having a good/better life will depend upon population controls and the evolution of capitalism into something that distributes the wealth more evenly (perhaps something beyond our current understanding with all the best points of socialism and capitalism)(perhaps something like "Participatory Economics"
http://www.zmag.org/parecon/indexnew.htm) .
As for energy sufficiency and alternative energy, I'm all for anything we can do--individually or as a nation/government to advance as rapidly as possible. I'm sure that includes a majority of us--but, alas, it does not include the immense Oil Companies (which more or less control the leadership of our government). To move ahead, it's going to take at least a considerable increase in the traditional kind of votes in the right amounts at the right times and places. Of course, we could have many more votes (and perhaps even an honest polling system) if we could finally create the desperately needed Libera/Democratic broadcasting network. All in all, I'd say--for now at least, we'd do better to take all the spare funds we might have with which to either buy U.S. or improve our fuel economy and send it in as either a donation or investment in a not-for-profit corporation for creation of such a broadcasting company (if only there were an organization to organize and collect such donations/investments--after some time, with some real success, we could literally buy/build a new network from scratch if need be!). Alas...