Results from a straw poll of libertarian Republicans highlight the senator’s shrewdness. Even before the 2016 presidential election cycle began, most observers expected the race for the Republican nomination to be a war of attrition—especially compared to the Democratic primary, where Hillary Clinton was expected to enter the race as a nearly prohibitive frontrunner. And so back in March, when Ted Cruz announced his campaign for president, it was easy to infer that Texas’s junior senator would be planning for a long campaign that would leave him as the last candidate standing at the end of the GOP nomination fight....