Alright, one more time, and this time, listen: you know how this needs to go to a full, thorough, and fair investigation? You said it yourself, right?
Trump was told ok, give us the documents that would make this a full, thorough, and fair investigation - for transparency purposes, it's the White House's job to record and maintain them. Trump did not. That's obstruction of justice. He's obstructing the full, thorough, and fair investigation. That's THE impeachable offense.