plan. they want to poke holes in the credibility of the special counsel team and raise questions about alleged bias by the special counsel, so all of the negotiations or the format really just a preview of tomorrow's very dramatic testimony as democrats hope this reshapes the narrative and the public understanding about alleged criminal conduct in the white house but others are downplaying the impact this will have and republicans hoping it does what the president has hoped, to show in his view that he was exonerated. >> manu raju on capitol hill. stand by. i want to bring in our crime and justice reporter shimon procku pez. why does he want the deputy by his side. >> he wants to protect mule tore give him cover. so they're hoping to have -- they were hoping to have him sit there and answer some of the questions that the committee members were going to have and what we're seeing here from the letter yesterday that the department of justice published from mueller asking for guidance about what he can testify to,