Here is the question Bernie Sanders had for House Impeachment Managers (Source Fox News): 

“Republican lawyers have stated … that two people, Senator Johnson and Ambassador Sondland, were told directly by President Trump that there was no quid-pro-quo in terms of holding back Ukraine aid in exchange for an investigation into the Bidens. Given the media has documented President Trump’s thousands of lies while in office, more than 16,200 as of January 20th, why should we be expected to believe that anything President Trump says has credibility?”

Here is the response he got from Rep Adam Schiff (Source Fox News): 

“If every defendant in a trial could be exonerated just by denying the crime, there would be no trial. It doesn’t work that way. I think it’s telling that when Ambassador Sondland spoke with President Trump, the first words out of his mouth, according to Sondland, there were ‘no quid-pro-quo.’ That’s the kind of thing you do. You blurt out when you’ve been caught in the act and you say, ‘it wasn’t me, I didn’t do it.'”