In Clinton impeachment, sex infidelities of Speaker designate Livingston, Burton, Chenoweth, and Hyde were exposed. This was perhaps a warning to others to acquit and remember blackmail material could be exposed. For Trump impeachment, if he goes to trial and wants to call witnesses like Schiff and Pelosi and other DS bad actors, Chief Justice Roberts presumably could rule they are not permitted. So the question I have is Roberts free of Blackmail risk?