Simmering discontent among a segment of Arizona Republicans over John McCain’s famous penchant for bucking his party boiled over in the winter of 2014 with the censure of the longtime U.S. senator. McCain’s allies responded with an all-out push to reassert control over the Arizona Republican Party. Censure proponents were ousted or diminished, and McCain went on to defeat his far-right challenger in a blowout during the 2016 primary. Less than a decade later, the right wing forces that McCain marginalized within the Arizona GOP are now in full control, with profound implications for one of the nation’s most closely...