" Instead, Giuliani pressed ahead, with Trump’s encouragement, to begin a full-scale investigation about Joe and Hunter Biden in Ukraine. If Giuliani had done anything else, Donald Trump would not have been impeached. For this reason, Giuliani’s work must rank among the most disastrous pieces of advocacy in the history of American lawyering. "

― Jeffrey Toobin , True Crimes and Misdemeanors: The Investigation of Donald Trump