So why would he need to call a witness for not showing up for a subpoena? If I was the prosecutor, I would ask the one and only question. "Did Steve Bannon show up for his subpoena?" Yes or no Buford what would your answer be? Buford, I'll let you in on a little secret. Bannon is blowing smoke up your rear. Buford do you remember a couple years ago he wanted you republicans to donate for the "border wall" and then used the money for his personnel stuff. He going to get to see a "wall" not the border wall but the prison walls. Remind me of a song by John Mellencamp "Crumbling down"
https://www.youtube.com/watch?v=FxSlYdIYQ7E