It looked like a marriage that could bring together the storied history of a century-old magazine and the culture-changing dynamism of Facebook.

But it didn't work.

The New Republic, a leading voice on the US political left wing since 1914, is up for sale again after Facebook co-founder Chris Hughes decided to throw in the towel less than four years after he bought the magazine.

Hughes, 32, invested more than $20 million in an effort to bring The New Republic into the digital era.

But on Monday, he acknowledged it was not working, saying, "I underestimated the difficulty of transitioning an old and traditional institution into a digital media company in today's quickly evolving climate."

Hughes, a Harvard roommate of Facebook co-founder Mark Zuckerberg and part of the original team at the social network, had faced friction with the editorial staff.

It turned into a full-scale revolt in 2014 when Hughes decided to shake up the top management and reconfigure the publication as a digital media organization.

Tina Brown, the former editor of The New Yorker and Vanity Fair, captured some of the venom Hughes aroused in her reaction to the latest development.

"Can't believe Hughes is unloading @NewRepublic after breaking it. Feckless rich dilettante smashes toy. @chrishughes," she wrote on Twitter.

Former New Republic staffer Jonathan Chait said Hughes had "a wildly unrealistic business strategy" that was aimed at ending losses.

This strategy "ignored all the evidence that was presented to him by people at the magazine including the fact that the magazine had never made money in its entire history," Chait told AFP.

Chait said the moves by Hughes sparked widespread departures, with many going to the online Huffington Post.

"None of them were reluctant to write online," he said. "They simply no longer trusted management."

- A 'distinct culture' -

The small but respected magazine, which celebrated its 100th anniversary in 2014 with an event attended by former president Bill Clinton among other notables, has survived over the years thanks to a series of benefactors.

"The New Republic was a small niche, with a very distinct culture," said Columbia University journalism professor Susan McGregor.

"The idea that you could treat it as a blank slate that can simply be remade as a digital media outlet doesn't really appreciate the fact that this organization has a deep history that is not going to be transformed simply because suddenly you ask people to have a Twitter account."

It's not clear if the troubles at The New Republic are a harbinger of things to come at other media outlets led by Internet entrepreneurs -- such as the Washington Post, bought by Amazon founder Jeff Bezos, or First Look Media group launched by eBay founder Pierre Omidyar.

McGregor said people who have been successful in Internet ventures have been attracted to media because "it's a way to make your mark in a very public way that is much more appealing than just making a lot of money."

Jay Bolter, a professor of communication at Georgia Tech University, said the two worlds are very different.

"There can be a cultural clash between journalists who have strong assumptions about their work and their audience and this new digital world that has a totally different background," he said.

Hughes said he will be seeking someone else to take over the publication, whether an individual, a larger digital media company, or a think-tank.

"Although I do not have the silver bullet, a new owner should have the vision and commitment to carry on the traditions that make this place unique and give it a new mandate for a new century," he said.