I don't think the problem is in the manufacturing jobs. The fact of the matter is that these jobs do not require as high qualifications as they may have in the past, therefore they correspond to a lower standard of living and end up in countries where people are more willing to accept such a standard.
It's analogous to the industrial revolution, when a machine can make something much faster and much better than a human with rudimentary tools, these old jobs become redundant.

Then with globalization americans also face more competition, so it seems reasonable that in the bigger pool you may end up being a smaller frog.

Of course, there's also the problem of businesses externalizing costs and selling it to politicians for money and to the joe-six-pack as anti-regulation and pro-business. And government waste appears to be only wasteful when it doesn't benefit the person making such determination.

The nature of free market is that it is conductive to creating big economic disparities. And, sadly, a lot of voters are pretty easy to manipulate with ideological propaganda, and don't understand that at the end of the day the more important thing in their life is the nature of the society they live in.

The american political system though is designed from day one to be based on elitism. But there is also the feedback from those not in power, who are the vast majority. As long as they are wiling to accept the way they are being ruled, that's how it ends up being (the congress reelection rates are around 90%, same as always). Unfortunately it seems to be often producing the worst of both worlds - corrupt establishment and incompetent populists.

It's always interesting to look at the polls who ask the quality questions without trying to bias them with ideology, e.g. what do they think is the level of economic disparity and what do they think it should be. Vastly different results than if you ask about tax cuts.