For decades, Senator Joseph R. McCarthy’s name has been used as shorthand for the opposite of the aspirational ideal of civilized American politics. In the way that Kleenex has become interchangeable with tissue, McCarthyism, for many, is an eponym for the unjust, reprehensible use of political power. Indicating that anything resembled the tactics and smears of the late senator from Wisconsin has been enough to suggest that such behavior was out of bounds, with no rightful place in our modern politics. But now comes a small, influential group of hard-line right-wingers who believe that, in the words of one popular meme in such circles, McCarthy was right. McCarthyite revivalism has flitted around the edges of American conservatism since the senator fell from grace during his conspiratorial anti-Communist campaign in the 1950s. In 1954, the conservative patron saint William F. Buckley Jr. and his friend and fellow conservative thinker L. Brent Bozell Jr. defended the senator in their book, McCarthy and His Enemies, as a sometimes-misguided figure unfairly maligned for his justified quest to root out …