Donald Trump didn't have a polling operation until very late in his campaign. How did he know what to do? That the Ted Cruz people leaked their polls to Trump because they were looking forward to eliminating all the other rivals, clearing the way for a Cruz-Trump fight that they were certain Cruz would win. In the end, Cruz was the last man standing, it's true. If he had known at the beginning what he knew at the end, he might have thought twice. The Congressional Republican Party thought they could make Trump their tool to impose their very unpopular agenda. Instead, they became his tool.