Speaking more generally, you've hit the crux of the issue. How do middle class* Americans improve their income when the corporations who hire them have a global hiring pool and are competing against workers who can live well off on $5/hr?
Sadly, IAM and its membership is in a no-win situation. Even if they "win" this battle, the long war is not favorable. China's emerging airplane companies, Embraer, Bombardier, etc are all creeping towards the 737/A320 market which are the stable revenue generators for Boeing and EADS. Can a unionized American company or a European consortium based in socialist countries compete against China or Brazil's marketplace and lax corporate/safety rules? I don't see how they could. Some day, IAM and SPEEA will probably be forced to accept lower wages so Boeing can compete with the new players, or else see Boeing go under altogether.
* Whatever definition you may assign to that