They can’t do anyhting about the Union plans without renegotiating the contracts which the Unions must agree to (No chance of that). Should be a big item on the table when the current contracts expire. You may see some strikes and shutdowns when this happens.
If it does, fire them.
Forgot to mention that something like this could influence the pending contract of the new Air Force Refueling Tanker competition between unionized Boeing and Non Union EADS which will build the plane in Alabama.