Van Hollen to GOP Senators: 'Be Very Careful' When Evidence Comes Out You Will Look 'Complicit In the Cover-Up'

On Monday's broadcast of MSNBC's  "All In," Sen. Chris Van Hollen (D-MD) told his Republican colleagues in the Senate that they should "be very careful," when voting on witnesses and documents in President Donald Trump's impeachment trail because more evidence of wrongdoing could come out.