09/18/2012 05:13 EDT | Updated 11/18/2012 05:12 EST

Carter's grandson gives Obama a gift after tracking down damning Romney video

WASHINGTON - It's been said that U.S. President Barack Obama has long bristled at suggestions he's another Jimmy Carter.

And yet the grandson of the 39th president has just bestowed a gift upon the 44th that could help Obama win re-election in November.

James Carter IV has come forward as the online sleuth who tracked down undercover videotape of Mitt Romney's damning comments four months ago to a US$50,000-a-plate Republican fundraiser in Florida.

In the tape, Romney belittles Obama voters as being government freeloaders who believe they're entitled to endless handouts from Uncle Sam. It's not his job to worry about those voters, Romney said in the video.

"I'll never convince them they should take personal responsibility and care for their lives," he said.

For Carter, his mission was personal — the 35-year-old online researcher, currently looking for work, said he'd grown sick and tired of Romney slagging his 87-year-old grandfather, a Nobel Peace prize winner who has long worked towards peace in the Middle East.

For 30 years, to the dismay of many Democrats, Carter's name has been used as shorthand by Republicans for a weak, ineffectual president. Since Obama's 2008 election, they've often gleefully compared him to Carter.

Carter's grandson, an overnight media sensation, is enjoying his revenge.

"I don't like criticism of my family," the younger Carter told NBC News on Tuesday after it emerged he'd persuaded the fundraiser attendee who secretly taped Romney to hand the video over to Mother Jones magazine.

"It gets under my skin. I'm proud of my role in being able to track it down. My motivation is to help Democrats get elected."

In an interview with The Associated Press, he added: "I've gotten a lot of Twitter messages from people supporting me and saying that it's poetic justice that it was a Carter that uncovered this, considering the way that the Romney campaign has been talking about my grandfather. I agree with that sentiment wholeheartedly."

His grandfather is proud of him, Carter added, sending him a message on Tuesday morning that read simply: "James: This is extraordinary. Congratulations! Papa."

The Atlanta-based Carter says it all began just prior to the Republican convention last month, when he noticed on YouTube a portion of the video that showed Romney talking about using Chinese labour while working at Bain Capital.

He tracked down the person who posted the video, "Anne Onymous," and convinced the poster to give the entire video to David Corn, the Washington bureau chief for Mother Jones magazine, a left-wing, non-profit investigative news outlet.

Carter had previously helped Corn do online research into Bain Capital's China dealings. He put the source in touch with Corn, and has been credited as a "research assistant" on the story.

"Any time that you can find a clip that strengthens the narrative already established, that's what becomes a big deal," Carter said. "I've been trying to get paid for this but it hasn't worked out yet. This might help."

Conservatives were foaming at the mouth Tuesday about Carter's involvement.

"Your (grandpa) worst Prez ever. Obama 2nd worst ever. Go to hell loser," one tweeted.

John Sununu, a Romney surrogate, seethed in an appearance on MSNBC while defending the Republican presidential hopeful's remarks.

"If Jimmy Carter's grandson hadn't snuck this out, we wouldn't be having this conversation today," hissed the former New Hampshire governor.

But at least one Democrat — and there were sure to be others — offered him a job.

Carter can "start tomorrow" at the Ohio Democratic party, its chairman Chris Redfern tweeted.