We already know that birthers are strongly committed to their wrongheaded views–which they hold for political and ideological reasons–and very driven to argue them. In this context, the White House’s surprise decision to release the president’s actual birth certificate may not have its intended effect.
Motivated reasoning theory suggests that this will not work to change the minds of the most committed–rather, new excuses will be created for why Obama was not born in the U.S. (or, some other new favorable argument will be constructed).
The White House’s approach may, however, be successful in driving birtherism entirely out of polite discourse. If it is viewed as untouchable throughout the media, and unutterable by all serious elected Republicans, then that is still a victory.
But while I’d be glad to be proven wrong, I don’t really expect hardcore birthers to suddenly change their minds. Rather, I would expect to see goalpost shifting.