LOL! Is there a particular reason why you chose to respond like an obnoxious potty-mouth, other than that your poor mother failed to teach you good manners?
Most H-1B's are hired because they are CHEAP!
OK, let's assume that's the case, and that they're cheaper than comparable Americans. It's most likely that the former H-1B jobs would be outsourced, rather than given to the more-expensive Americans. Especially since the outsourced engineers would be far closer to the manufacturing side of the equation.
In any event, I stand by my prediction that the unemployment rate here would be unlikely to change much if the H1B folks were let go.
Are you in the industry ?