(CNN) - Christopher Buckley, the son of conservative icon William F. Buckley, said Tuesday he's resigned from the conservative National Review days after endorsing Barack Obama's White House bid, among the most powerful symbols yet of the conservative discontent expressed this election cycle.
In an online column, Buckley said he had decided to offer his resignation from the magazine his father founded after hundreds of readers and some National Review colleagues expressed outrage he was backing the Illinois senator.
"While I regret this development, I am not in mourning, for I no longer have any clear idea what, exactly, the modern conservative movement stands for," Buckley wrote.
"Eight years of 'conservative' government has brought us a doubled national debt, ruinous expansion of entitlement programs, bridges to nowhere, poster boy Jack Abramoff and an ill-premised, ill-waged war conducted by politicians of breathtaking arrogance. As a sideshow, it brought us a truly obscene attempt at federal intervention in the Terry Schiavo case," he also wrote.
The resignation comes four days after Buckley formally endorsed Obama on the Web site The Daily Beast, writing the presidential campaign had made John McCain "inauthentic," and Obama appeared to have a "first-class temperament and first-class intellect."
In a statement posted on the publication's Web site Tuesday, National Review editor Rich Lowry noted Buckley was writing for the magazine on a trial basis, and took his offer to resign with the "warmest regards and understanding" sincerely. Lowry also took issue with Buckley's contention the magazine had been flooded with angry mail over Buckley's endorsement, saying it had received a relatively small 100 e-mails expressing disapproval.
"It's an intense election season and emotions are running high," Lowry said.
Matt Lewis, a contributing writer to the conservative Web site Townhall.com, told CNN the National Review made the right decision in quickly accepting Buckley's resignation.
"While it is acceptable for a conservative to vote for a third party – or to abstain from voting for McCain – no real conservative could cast their vote for Obama," he said. "The conservative movement didn’t leave him, he left it.
But in his column Tuesday, Buckley expressed disappointment the magazine, and conservatives in general, were not more open to dissenting opinions that his own father once championed.
"My father in his day endorsed a number of liberal Democrats for high office, including Allard K. Lowenstein and Joe Lieberman," he said, adding later, "My point, simply, is that William F. Buckley held to rigorous standards, and if those were met by members of the other side rather than by his own camp, he said as much."
Buckley is only the latest among several prominent conservative to express dissatisfaction with McCain and his running mate Sarah Palin. David Brooks, Kathleen Parker, David Frum, Peggy Noonan, and George Will, all high-profile conservative thinkers, have each openly criticized the ticket over the last month.
"Sadly, I think Christopher Buckley is merely the latest example of the 'conservative' avant-garde who has succumbed to a common temptation: Becoming more liberal is tantamount to becoming more open-minded. There is a palpable elitism among some of the conservative panjandrum," Lewis said.