By Kay Henderson
DES MOINES (Reuters) - Likely Republican presidential candidate Tim Pawlenty, speaking to conservative Tea Party backers, separated himself from potential party rivals like Donald Trump over the "birther" issue on Saturday
Addressing a Tea Party rally in Iowa's capital, the former Minnesota governor did not -- as real estate mogul Trump has done -- embrace conspiracy theorists who claim that President Barack Obama was not born in the United States.
"Now, I'm not one to question the authenticity of Barack Obama's birth certificate," Pawlenty said. "But when you look at his policies, I do question what planet he's from."
Pawlenty also said Congress should not vote to raise the federal debt ceiling, suggesting that would be a "license" for the Obama administration to "spend more money."
One of the organizers of Saturday's Tea Party gathering described it as an "iced tea" rally as temperatures hovered around 40 degrees, with whipping winds making the wind chill feel more like 30 degress.
Also speaking at the outdoor rally, which drew more than 300 supporters, was former Godfather's Pizza CEO Herman Cain, who said he was "weeks away" from making a final decision about a run for the White House.
"In January I had put my toe in the water, but I'll just give you a little hint," Cain said. "It's now all the way up to my chin," Cain said, to cheers from the crowd.
Cain told the crowd about his battle with cancer in 2006, saying he's been "totally cancer free" for the past five years.
"You want to know why? God said, 'Not yet Herman,'" Cain told the crowd. "God said, 'Not yet. I've got something else for you to do.' And it might be to become the president of the United States of America."
(Reporting and writing by Kay Henderson; Editing by Mary Wisniewski and Peter Bohan)