The significance of this NBC/Wall Street Journal poll is two fold. First, it is the first poll to be conducted completely after the news of Antonin Scalia’s passing and Trump’s meltdown at the South Carolina CBS News debate. Second, it is from a highly respected pollster focused on likely voters and who has a good track record of success. The poll shows Ted Cruz in the lead now. It could be an anomaly. But internal polling of several campaigns all show the South Carolina race far tighter than the public polling. This latest poll, however, does not account for Nikki...