There are plenty of reasons to be cautious of national polls that show Trump and Carson leading. They may fail to screen out casual voters, for instance, and leaders at this point in past years have eventually tanked. But perhaps the biggest reason to ditch stock in these polls is that they’re simulating a national vote that will never take place. In reality, the GOP nominating contest will be decided by an intricate, state-by-state slog for the 2,472 delegates at stake between February and June. And thanks to the Republican National Committee’s allocation rules, the votes of “Blue Zone†Republicans...