Trump challenges Biden to a cognitive test. Mixes up name of doctor CNN 0 176 06.17 20:15 https://www.youtube.com/watch?v=zOb1xrAuop8 + 38 https://www.youtube.com/feeds/videos.xml?channel_id=UCupvZG-5ko_eiXAup… + 30 Trump challenges Biden to a cognitive test. Mixes up name of doctor