Gov. Rick Perry attempted to quiet the birther speculation Wednesday, in an exclusive interview with Tampa’s Bay News 9, saying he has “no doubt” President Obama was born in the United States and people need to “lighten up” about it.

In an interview to air Sunday, Perry was asked if he believes Obama is an American citizen.

“I have no doubt about it,” Perry said.

Speculation over Perry’s position on Obama’s citizenship first arose in an interview in Parade Magazine last Sunday.

Perry says he was only joking when he made comments about the president’s birth origin in a television interview earlier this week.

“I don’t think I was expressing doubts.  I was having some fun with Donald Trump,” Perry said.  ”It’s fun to, you know, lighten up a little bit.”

Perry borrowed the “lighten up” line,  from Herman Cain, who uses it as a staple of his stump speech.  Cain also attempted to turn a political gaffe into a joke when he proposed an electrified border fence to enhance border security.

“It’s a joke,” Cain said the next day.  ”I’ve also said America needs to get a sense of humor.  That was a joke, ok?”

Perry, who released his 2010 tax returns earlier this week and whose lackluster college transcripts came under scrutiny this summer,  issued a challenge to President Obama and other politicians.

“Let’s lay out our income taxes, let’s lay out our college transcripts, mine’s been on the front page of the paper.”