Why Norah O'Donnell is trending

<p>US President Donald Trump had a contentious exchange with CBS News’ Norah O’Donnell during an interview on “60 Minutes.” CNN’s Brian Stelter breaks down what led to Trump calling O’Donnell a “disgrace." Discover more videos, including live streams and exclusive storytelling, on our <a href="http://cnn.com/watch">Watch</a> page.</p>