Frum has long been a voice of sanity in the wilderness of modern conservatism--long before Bill Kristol and the other Never-Trumpers spoke up. I wrote about him in Blowing Smoke, back in 2010. This is what I wrote:

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When John McCain selected Sarah Palin as his running mate, Frum called the decision “a huge mistake.” He later said of Palin, “Her divisiveness is not just within the country, it’s divisive within the party.” He also wrote a Newsweek article titled “Why Rush Is Wrong” and called Glenn Beck’s success “a product of the collapse of conservatism as an organized political force, and the rise of conservatism as an alienated cultural sensibility.”

After the health care bill passed, Frum chastised Republicans for obstructing when they should have been compromising. Calling the bill’s passage the Republican’s “Waterloo,” he wrote:

We followed the most radical voices in the party and the movement, and they led us to abject and irreversible defeat. There were leaders who knew better, who would have liked to deal. But they were trapped. Conservative talkers on Fox and talk radio had whipped the Republican voting base into such a frenzy that deal-making was rendered impossible. How do you negotiate with somebody who wants to murder your grandmother? Or—more exactly—with somebody whom your voters have been persuaded to believe wants to murder their grandmother?

Most compellingly, Frum has hammered at the very foundations of persecution politics, eloquently explaining how the rise of Rush Limbaugh, Glenn Beck, and Sarah Palin has turned the conservative movement on its head. He wrote:

Back in the 1960s and 1970s, we’d been fighting to protect the common-sense instincts of ordinary people from elite interference. Now, in the Terri Schiavo euthanasia case, with stem cell research, on gay rights issues, it was we who had become the interfering elite, against a society that was reaching its own new equilibrium. Of course, that’s not how conservatives saw it. We saw a country divided in two, red states and blue, NASCAR vs. NPR, real America against the phonies in the cities. A movement that had begun as an intellectual one now scornfully pooh-poohed the need for people in government to know anything much at all...Instead, we rallied to Sarah Palin and Joe the Plumber.

For these opinions, Frum has become a pariah within his own party who is regularly trashed on the right-wing blogs. You won’t find Frum on Fox News these days. The only media commentators who seek his opinion want to ask him about his critical views of the conservative movement. The Wall Street Journal, which had once lavished such praise on its former editor, editorialized, “Mr. Frum now makes his living as the media’s go-to basher of fellow Republicans, which is a stock Beltway role. But he’s peddling bad revisionist history that would have been even worse politics.” The American Enterprise Institute ended Frum’s fellowship days after his widely publicized (and denigrated) Waterloo column. While its president denied that the dismissal had anything to do with Frum’s article, the timing led analysts—and Frum himself—to conclude otherwise.