A standing president can only be impeached by committing treason or high crimes.
Clinton was impeached for lying under oath.
Ok, so lets make Obama testify on the Libyan attack then. Lets cross reference him on why he & other high ups instructed for false statements to be made to not only the American people but the world. Ask him why he flat our lied about the events surrounding the attacks. IMO he already lied under oath, he took a oath when he took office & he has broken that oath.