Call them "unicorners." A liberal group says it has collected more than 19,000 e-mails requesting Arizona officials to confirm Mitt Romney is not a unicorn.

Without such proof, the group Left Action argues with tongue in cheek, Romney may indeed be a unicorn -- his dark mane hiding a horn -- and therefore ineligible to be on the presidential ballot in November.

The farcical campaign mimics efforts by so-called "birthers," and some top supporters of certain Republican presidential nominee Mitt Romney, to continually raise the already-settled issue of whether President Barack Obama meets the Constitution's requirements for citizenship.

"I feel like we've tried logic with the birthers for too long," Left Action founder John Hlinko told CNN on Wednesday. "Now it's time to take their arguments to the logical extreme to show how absurd they are."

While steeped in satire, the unicorn-birther matter touches on deeper issues as Obama and Romney head into the November campaign.

Since before Obama's election in 2008, some conservatives have questioned whether he was born in the United States. If not, they said, he was ineligible to serve as president.

Despite conclusive evidence to the contrary, the issue has remained alive, nurtured by the conservative blogosphere and getting raised repeatedly by Republican figures.

Donald Trump, whose 2011 crusade to unearth details about Obama's origins drew global attention and prompted the White House to release the president's long-form birth certificate, raised the issue again last week.

Before campaigning with Romney on Tuesday, Trump bristled when told by CNN's Wolf Blitzer that he was beginning to sound "a little ridiculous" for characterizing the question of where Obama was born as a matter of opinion, rather than fact.

"You are, Wolf," Trump fired back. "Let me tell you something, I think you sound ridiculous."

Wolf Blitzer responds to his Donald Trump interview, says if Trump is going to back up 'birther' claims, he has to have evidence

The Romney campaign appears anxious to distance itself from the birther issue. When asked Monday about Trump's raising it, Romney said he believes Obama was born in the United States.

"You know, I don't agree with all the people who support me and my guess is they don't all agree with everything I believe in," Romney said. "But I need to get 50.1% or more and I'm appreciative to have the help of a lot of good people."

Obama's campaign jumped on that comment, with deputy manager Stephanie Cutter issuing a statement Tuesday that said Romney's "continued embrace of Donald Trump and refusal to condemn his disgraceful conspiracy theories demonstrates his complete lack of moral leadership."

Meanwhile, the Romney campaign accused Obama supporters of using the issue to distract attention from the high unemployment rate. Romney surrogate John Sununu, a former New Hampshire governor, went further Wednesday, accusing CNN of deliberately focusing on the birther issue in support of Obama.

"Why is CNN so fixated on this? Why don't we talk about the jobs issue in this country?" Sununu asked after CNN's Soledad O'Brien raised the birther issue to start an interview. "It's CNN that wants to bring it up. I don't want to bring it up. Mitt Romney made it clear that he believes that President Obama was born in the United States."

When O'Brien responded that Trump's raising of the birther issue made it a valid question about a possible major contributor to the Romney campaign, Sununu fired back that comedian Bill Maher -- known for politically incorrect commentary -- is a Democratic supporter.

"The fact is that this country has a jobs problem, and supporters of the president like CNN keep wanting to talk about other issues," Sununu said.

Pressed on the matter by O'Brien, Sununu declared: "It's not an issue. There is nobody in the Romney campaign that believes that the president was not born in the United States. Donald Trump is wrong. The president is born in the United States."

Hlinko of Left Action called Sununu's pronouncement "a good start," but he called on Romney and other Republican leaders to make that point directly to birthers to halt what he labeled a racism-tinged attempt to delegitimize the nation's first African-American president.

"It is the Republican grassroots and Republican leaders who keep on raising it," Hlinko said of the birther issue, adding that Romney and other GOP leaders "refuse to actively push back."

"They're not just saying, 'This is nonsense and it's tinged with racism and it needs to stop,' " Hlinko said.

While targeted at Romney, the unicorn campaign actually is satirizing last week's justification by Arizona Secretary of State Ken Bennett for threatening to bar Obama from the November presidential ballot.

Bennett, who initially said his office received 1,200 e-mails from Arizonians questioning whether Obama was born in Hawaii, said that he was duty bound to investigate that public concern.

It didn't matter that the White House last year released Obama's long-form birth certificate from Hawaii. Trump and others question whether the document is authentic, and Sheriff Joe Arpaio of Arizona's Maricopa County -- known for his tough crackdown on illegal immigrants -- has sent a deputy to Hawaii to check it out.