Trump is King of the Birthers. What is there for him to challenge?
I'm liking what Trump is doing to/in this campaign, but that episode a few years back was akin to many of the "teasers" we've gotten from Whore-aldo, Hannity, Monica Crowley, and yes, even Breitbart. It may become his Achilles' Heel.
So, you buy the meme that the b/c is legit? Seriously.