Robert Mueller's latest subpoena could cross Trump's 'red line'

Andrea Mitchell Reports 3/16/18
Robert Mueller's latest subpoena could cross Trump's 'red line'

President Trump once said looking into his personal finances would cross a "red line." MSNBC legal analyst Ben Wittes says Robert Mueller's latest subpoena could be the kind of thing that Trump would think of as an "escalation." Duration: 7:29