Obstruction itself is a crime and Trump and his minions, at his direction, lied about obstruction. Nevertheless, an underlying crime is not an element for obstruction of justice. Clinton got hit for obstruction of justice for allegedly lying in a civil deposition. Certainly no underlying crime in relations with a twenty-something intern. Thanks be to God. What Trump was covering up with in his obstruction was a legitimate investigation into crimes by a foreign power and several Trump associates who either plead or were found guilty.