According to PPP:
Only 38% of Republican primary voters say they're willing to support a candidate for President next year who firmly rejects the birther theory and those folks want Mitt Romney to be their nominee for President next year. With the other 62% of Republicans- 23% of whom say they are only willing to vote for a birther and 39% of whom are not sure- Donald Trump is cleaning up. And as a result Trump's ridden the controversy about Barack Obama's place of birth to the highest level of support we've found for anyone in our national GOP polling so far in 2011.
Tom Jensen notes that even if Trump doesn't run "someone who taps into the same sort of hard, hard right sentiment he's appealing to right now will get their votes- it's hard to imagine these folks voting for a more centrist candidate like Romney or Pawlenty." Ben Smith dismisses the poll:
Who seriously thinks Republican primary voters spend much time thinking about whether birth certificate views disqualify a candidate, much less are going to vote on those purported views. It's really a great example of the deep irrelevance of most early polling.