By common consent, William F. Buckley Jr., who died last Wednesday, was the father of modern conservatism. But he also ended up as one of the Bush administration's most trenchant critics. His death not only represents the loss of one of America's leading intellectual figures but also underscores the extent of the collapse of the conservative movement that has shaped politics so decisively for decades.

Like no other personality, Buckley pulled together the disparate strands of the conservative movement to endow it with panache, self-confidence and a sense of being on the cutting edge. An avid sailor, a writer of numerous spy novels and the host of the first of the political talk shows, "Firing Line," Buckley quickly became a celebrity who made conservatism respectable.

This was no small feat in postwar America. After the defeat of Nazi Germany and the widespread acceptance of the New Deal, conservatism looked like a relic, consisting of a bunch of isolationists and anti-Semitic cranks. The journalist Murray Kempton, who later became a close friend of Buckley's, summed up the dominant liberal thinking at the time when he observed, "The New American Right is most conspicuous these days for its advanced state of wither."

Buckley changed that.

With the appearance of National Review in 1955, he began to give conservatism a makeover. No doubt Buckley's greatest flaw was his embrace of Sen. Joseph McCarthy and his refusal to acknowledge McCarthy's malevolence. But Buckley himself was a tolerant figure whose best friends (such as the radical journalist Dwight Macdonald) were often on the left. He never confused, as today's conservatives often do, shared political views with actual friendships.

A year after graduating from college, Buckley pioneered the depiction of American liberals as a smug, self-satisfied elite in his famous 1951 book, "God and Man at Yale." At National Review, he brought on a passel of former Trotskyites turned conservatives, such as Willi Schlamm and James Burnham, who churned out essays attacking the news media and universities as being filled with doctrinaire liberals. Sound familiar?

Ever since, conservatives — whether it's Ann Coulter or Dinesh D'Souza — have denounced traitorous liberal elites. But they are bargain-basement Buckleys. The difference is that Buckley's criticisms were grounded not in personal venom but in analysis. In the 1960s, after all, liberals really did have the upper hand in politics; they dragged the U.S. into Vietnam and oversaw the rise of the Great Society, which became a big conservative bugaboo.

Even as debate raged, however, Buckley never became a hater. He possessed a benignant temperament that his successors lack. His most famous proteges — writers Garry Wills, Joan Didion and John Leonard — eventually decamped for the left. Buckley's response was to quip, "I hadn't realized that I was running a finishing school for young apostates."

In the end, Buckley's judicious temperament and inquisitiveness meant that he himself became something of a heretic, ironically at the moment the right seemed to be at the peak of its power. When I met Buckley, then nearing 80, for lunch at (where else?) the New York Yacht Club in 2004 to interview him about neoconservatism, he was plainly skeptical of the idea that the Middle East could be turned overnight into a bastion of democracy. As the Iraq war became more of a morass, Buckley declared that the "insurrectionists in Iraq can't be defeated by any means that we would consent to use," and that in a parliamentary democracy President Bush would have had to step down.

Sam Tanenhaus, who is writing a Buckley biography, noted in the New Republic that Buckley also had begun to question "the wisdom of having opened the gates quite so wide." Into his movement had stepped neoconservatives and evangelicals who were bent on that most unconservative of propositions — a war to spread peace in the Middle East. The younger generation now running National Review largely has adopted that neoconservative worldview, much to the older generation's chagrin.

The poignancy of Buckley's predicament came home to me that blustery spring day outside the Yacht Club when two young foreign tourists recognized him and took a picture with him. Buckley was elated. The old, familiar grin surfaced for a moment. A troubled expression then returned, we shook hands, and he melted into the crowd. I had the sense that he feared being forgotten. But it is conservatism that is marooned by his death. Perhaps his memory can serve as a beacon for the movement he once guided to return to the solid shores of his — dare one say it? — liberal conception of conservatism.

Jacob Heilbrunn is a senior editor at the National Interest. He wrote this commentary for the Los Angeles Times.