WASHINGTON - Texas Gov. Rick Perry, struggling to claw back to prominence in the Republican presidential race, is renewing the so-called birther issue, suggesting in a new interview he harbours doubts that President Barack Obama was born in the United States.

"I don't have any idea," Perry told Parade magazine when asked if he believes the long-form birth certificate Obama released in April, largely to silence real estate mogul Donald Trump's assertions that the president wasn't born in the U.S., was authentic.

"I had dinner with Donald Trump the other night," Perry said. "He doesn't think it's real."

When the Parade interviewer reminds Perry that he's seen Obama's birth certificate, Perry replied: "I don't know. Have I?"

Earlier this year, Trump delighted the "birthers," a neoconservative collection of conspiracy theorists, when he flirted with a presidential run and made repeated, high-profile suggestions that Obama was unlawfully holding office because he wasn't born stateside.

Trump seized upon the birther movement despite the fact that most Americans regard the unfounded allegations with a collective eye roll. The brash businessman said he was proud of himself when a visibly annoyed Obama announced he'd released his Hawaiian long-form birth certificate in order to put the boots to an issue he called "silliness."

On that front, anyway, Perry agreed with Obama in the Parade interview.

"It doesn't matter," he said. "He's the president of the United States. He's elected. It's a distractive issue."

Nonetheless, Orly Taitz, the so-called Queen of the Birthers, is endorsing Perry's candidacy. She told the ThinkProgress website that she believes if the Texas governor wins the Republican nomination, he'll use the birther issue to attack Obama.

Taitz has filed several unsuccessful lawsuits attempting to disqualify Obama, whose father was Kenyan, from holding office. A federal judge said last week he was fed up with the "Sisyphean quest to prove that Obama is using a fake Social Security number and a forged birth certificate" as he dismissed Taitz's latest lawsuit.

The birthers have equally vexed Obama.

He referred to them as "carnival barkers" in April amid persistent accusations from the movement's adherents that he's unlawfully occupying the White House because he was born in either Kenya or Indonesia.

But he's not the only politician with a minority background in the crosshairs of the movement that's lost significant momentum since Obama took the unprecedented step of releasing his long-form birth certificate.

Recent accusations against two up-and-coming Republican politicians suggest the movement isn't fuelled by partisan politics, but something more sinister.

Senator Marco Rubio of Florida, the son of Cuban immigrants who's widely touted as a possible vice-presidential nominee, and Bobby Jindal, the Republican governor of Louisiana, are now taking heat from the birthers.

Charles Kerchner, a birther lawyer, recently obtained the naturalization petitions of Rubio's parents, who emigrated to Miami from Cuba in 1956. The Rubios didn't become citizens until 1975, prompting Kerchner and Taitz to assert the senator would be ineligible to be president since his parents weren't American citizens when he was born.

"Senator Marco Rubio is not a natural-born citizen of the United States to constitutional standards," Kerchner wrote on his blog. "He was born a dual citizen of both Cuba and the U.S.A. He is thus not eligible to serve as the president or vice-president."

Same goes for Jindal, the son of Indian immigrants, says Kerchner.

"Jindal is NOT a natural-born citizen of the United States," Kerchner wrote. "His parents were not U.S. citizens when he was born."

Rubio's office told Florida's St. Petersburg Times that the senator considers himself a natural-born citizen because he was born on U.S. soil. The U.S. Constitution, in fact, fails to define what is meant by "natural-born citizen."

The birther's new tactics have proven they aren't fuelled by party politics, the Washington Post's Dana Milbank wrote on Sunday, but are attacking politicians based on their race. He urged Republicans to distance themselves from the "angry and unstable in their ranks."

"Now that the birthers have begun to eat their own brightest prospects, perhaps Republican lawmakers will finally feel compelled to say something," he said in a piece written before Perry's remarks became public.