The problem was, there were several witnesses who delivered corroborated, sworn testimony implicating Trump of crimes, including a type of bribery (QPP) and abuse of power.
Mulvaney copped to the QPP on television, realized his error and recanted what he said on the video recordings. How much proof do you need?
Later, he effected obstruction of Congress by refusing to release documentation and continues to do so.
Despite Slobodan's partly valid excuse of "innocent until proven guilty", you can't in your wildest dreams call the Senate shenanigans a fair trial. Withholding evidence remains a crime.
You're okay with this stuff? You really think this is "all just politics"? You really think he's innocent?
Or are you just playing politics yourselves?
Annnnd ... no.
Mulvaney was making the point that all foreign affairs involve a QPQ, like every single one. And the vast majority of the time, it is not illegal.
Furthermore, the President is allowed to claim privilege and deny the house documents as he sees fit. This is not obstruction, but regularly excepted practice by the courts. Now, if the house disagrees, they can then take the President to court and argue their case,
which they did not do. It is only after a judge rules in favor of the house and president still refuses, that it become obstruction.
In this case, since the house refused to argue any subpoenas in court, Trump can not be legally guilty of obstruction. They even went so far as to retract Bolton's subpoena after Bolton himself went to court to see if he could testify.