Rep. Zoe Lofgren: Trump has "tried to obstruct every single member of the administration from appearing"
In an exclusive interview with "CBS Evening News" anchor Norah O'Donnell, four House impeachment managers outline their case against President Trump in the Senate impeachment trial. Watch more of O'Donnell’s interview with Representatives Zoe Lofgren, Jason Crow, Val Demings and Adam Schiff on Tuesday's "CBS Evening News" at 6:30 p.m. ET.