Donald Trump already said he has "just a little doubt" that Obama was born in the U.S. But now, according to TPM, he's going "Full Birther:"

Donald Trump tripled (quadrupled?) down on his emerging birtherism this morning on Fox & Friends, saying that since he first brought up the issue, "all of a sudden, a lot of facts are emerging and I'm starting to wonder myself whether or not he was born in this country."
...
He continued: "Now, this guy either has a birth certificate or he doesn't. And I didn't think this was such a big deal, but I will tell you, it's turning out to be a very big deal because people now are calling me from all over saying, please don't give up on this issue. If you weren't born in this country, you can not be president."

Wow.