"But obviously there is something there that the president doesn't want people to see on that birth certificate, that he sees going to great lengths to make sure it isn't shown. And that's perplexing for a lot of people," she added.
Several non-partisan watchdog groups long ago determined a certificate provided by then-candidate Obama, definitively proves he was born in Hawaii in August 1961.
There were birth announcements in local papers and statements from officials in Hawaii.
While Trump's questioning of where Obama was born has many scratching their heads, some say there's a method to his madness as he decides whether to run for president.
In the last three weeks, Trump's poll numbers have nearly doubled.
A new NBC News/Wall Street Journal poll among Republican primary voters shows Trump behind former Massachusetts Gov. Mitt Romney and tied with ex-Arkansas Gov. Mike Huckabee.
The website, ShouldTrumpRun.com,which has received more than 735,000 hits, and is hoping to convince Trump to run.
But while it may boost his visibility now, some analysts say it is bad long-term strategy.
Ari Fleischer, former press secretary for President George W. Bush, said the birther issue trivializes Trump and damages his brand.
"Everybody knows Donald Trump is entertaining, but you cannot become president of the basis of being a good entertainer," said Fleischer. "You have to run for president on issues that make people say I can see that person being the president, he acts presidential and the birther movement will not be the cause that propels Donald Trump forward it actually will be the cause that holds him back."