department attempted to improperly interfere with the annual audit of the president or vice president's tax returns, a process that is quote supposed to be walled off from political appointees and interference. joining us is tom hamburger of "the washington post," one of the reporters who broke that story. congratulations, viewers of this show have been following this story for a long time. how did you reach this breakthrough, and what's your understanding of the latest? >> we did understand, as you pointed out there were hints. chairman neal alluded to it in a court filing for that ongoing case he has seeking the president's tax returns. and once the very explosive charges from the intelligence community whistle-blower burst forth, there was more attention looking back. is there a second whistle-blower? we found that this second whistle-blower has emerged. we were able to talk briefly with this individual. and we talked also with chairman