Here is
a list of Toyota's factories in America.
Here is
a list of GM factories all over. Please take your time to count the US plants and compare with Toyota.
The rest, you'll have to do yourself.
Type into Wikipedia "list of [insert automaker here] factories" as a query. Do this with several automakers. Compare their domestic plants with GM's domestic plants.
Are you really complaining that GM is investing in a plant in Mexico? Why don't you complain instead that Nissan doesn't do enough to support the US economy? Why don't the Japanese complain that Honda is building a couple of plants over here? I'll answer this one for you. Even the Japanese, living in a culture inundated with advertising propaganda, understand that building one car in one country is a great publicity stunt that earns sales. Unfortunately, Americans ignore the obvious logic that building all cars here is expensive.
Let's do some math. Let's assume that all executives, workers, and everyone else makes the same exact money. If a factory in America has more expensive land, insurance, and technology, then the otherwise even playing field is no longer even. That cost has to be offset by reducing wages for someone. Now workers cost more, so executives have to make even less. Now all the good ones go to companies that pay them more. The product begins to suck. The organized workers begin striking over pay and benefits. Crippled by production loss, the company must comply. Quality sucks. Everything sucks with the exception of Corvettes and trucks.
For reasons hard for me to identify, this is when GM found pride. GM remembered that it is a company built in America by Americans, and those people deserve the best damned cars out there. The best car won, and that's why we drive Camaros instead of 370Zs or Geneses. The CTS kicks ass, and so does the Malibu, Cruze, and everything else.
GM did this because costs were reduced. GM is going to stay in business this time by making good business decisions. I don't want to question GM's decision to invest in a Mexican plant. I'm just happy to see GM in business as an American-managed company. Let's not go nuts and expect everything to get made here.