It strikes me that the attack on Unions by state government (including teachers unions) may have an validation or refutation through some more reporting on the BUY USA story line that Diane Sawyer has been reporting for the last week.
I think it would be good to include data in your report that answers the question "what percentage of the Made in USA items were made with Union labor." I don't know what the answer would be, but have a suspicion (along with the governors of several states) that the unions are a big cause of stuff going off shore because union contracts make products (and in the case of schools and government) and services non-competitive. It would be a great way to tie the story lines together and educate us on what is really the case (i.e. your story showed us we could buy USA products at competitive rates--but can we do that even if the products are made with union labor?).