Is Boeing looking to move out of its Washington home?

Boeing looks like it is expanding operations in the south of the US, having recently acquired a fuselage-assembly facility in Charleston, South Carolina. The possibility of it housing its second 787 assembly line there has also increased, which could signal the beginnings of a shift away from its Washington base.
The major reason for this is that the manufacturer appears to consider the Machinists union in Washington to be too strong - unions are much weaker in South Carolina, for instance. The International Association of Machinists and Aerospace Workers, which represents about 25,000 Boeing machinists in Washington, is already said to be reeling from the prospect of Boeing housing a new assembly plant anywhere but Washington. The union and Boeing are reported to be at loggerheads over a no-strike deal the manufacturer would insist on in selecting a production site.
The complexities of the 787 production process appear to have given Boeing the chance to decrease its reliance on the union and its Washington home, thus putting it in a stronger bargaining position, at the very least. But then we have already seen that Boeing's decision to outsource parts of the 787 construction to outside contractors sparked a major strike at factories around Seattle; one of the major reasons for the lengthy delay in getting the 787 to the market.
As well as Washington and South Carolina, Boeing is believed to be looking at sites in Texas and other southern states for the second 787 assembly plant, as it bids to ramp up production to make up for the lengthy delays. It will select a site for the new assembly line by the end of the year.