In the ongoing Senate impeachment trial, the White House’s defense of President Donald Trump hinges on keeping damning documents and witness testimony out of evidence. That is why, for the first time in our history, a president has defied every request for documents and witnesses from House impeachment investigators, and gone to extraordinary lengths to stop members of his own administration from testifying.

We have a party, in a trial, who controls the witnesses who know his true conduct, and that party is using that control to block important witnesses from testifying.