Wow, American Apparel was one of the last companies to make cloths in the US. That was part of their core branding.
Americans have proven over and over again at the cash register that "Made in the USA" justifies no more than a tiny price premium, if any. That's why the remaining L.A. factories crank out cheap stuff almost exclusively.
There is still a significant market for higher-quality garments, rather than the generic $10 T-shirt everyone is referring to, however in this area the USA's big problem is that the art has been lost. Those giant garment factories that used to dominate the landscape in North Carolina are long gone, and the talent has since retired or moved on to other careers.
And Canada, China, and Turkey are already doing quality apparel production faster, better, and cheaper than any US company will ever be able to. The barriers to re-entry are just too high - there is not enough money in it and too much government remains in the way.