Bookish types were important to the early rumblings of reform conservatism. And some of the earliest books on the need to rethink conservatism quickly put their authors on the Index of Forbidden Thinkers.

David Frum might be seen as a “premature reformer,” in the manner of those whom parts of the left once labeled as “premature anti-Communists” because they broke with the Popular Front before others decided it was fashionable to do so. Frum’s searing criticisms of his own camp (beginning with his open disgust at McCain’s choice of Sarah Palin as a running mate in 2008) made many conservatives unhappy enough to excommunicate him. Although the story is told differently by different sides, Frum’s dissidence had something to do with his departure from (or his being asked to leave) the American Enterprise Institute in 2010. His break with AEI happened to come only a few days after he lambasted the Republican Party for its failure to negotiate with the Obama White House over the Affordable Care Act. Frum’s heresy included acknowledging that the ACA had “a broad family resemblance to Mitt Romney’s Massachusetts plan,” building on “ideas developed at the Heritage Foundation in the early 1990s that formed the basis for Republican counter-proposals to Clintoncare in 1993-1994.”

Against Republican cries that Obama was leading the nation to socialism, Frum insisted (correctly, as it happens) that “the gap between this plan and traditional Republican ideas is not very big.” He also earned the opprobrium of many a conservative talk show host—and coined a highly useful term—by declaring the bill’s passage “a huge win for the conservative entertainment industry.” Their “listeners and viewers,” he wrote, “will now be even more enraged, even more frustrated, even more disappointed in everybody except the responsibility-free talkers on television and radio.”