Trump could not commit obstruction by definition
That's just not true. See Martha Stewart. And 50 million other legal "experts" that answered this 50 million times when released. Proving intent is the tough piece with an obstruction case.
Edit: See this summary from Politifact. But all this is a waste of time man. The election is how we should judge this piece of shit.
Obstruction of a non-crime?
Legal experts told us that a president (or anyone) could still be prosecuted for obstructing justice if they believed they might be prosecuted — even if they ultimately never are.
"You can obstruct justice even if a prosecutor ultimately finds you were not guilty of committing the crime that was the focus of the underlying investigation," said Miriam Baer, a professor at Brooklyn Law School. "Even if a prosecutor ultimately concluded that you weren’t guilty of crime X, that says nothing as to whether you thought that you might be indicted for crime X, or, for that matter, if you thought one of your friends of family members would be indicted for crime X."
Eric Posner, a professor at the University of Chicago Law School, agreed that an obstruction prosecution could have been argued in this case.
"Suppose Trump knew that no crime had been committed but believed that the investigation would uncover politically or personally embarrassing information, or if he believed that the investigation would embarrass or implicate an ally, aide, or family member," Posner said. "Then interfering with the investigation is a crime. The reason is that the purpose of the investigation is to find the truth, and if people obstruct an investigation, then the investigation becomes more difficult, wasting government resources."
That said, an obstruction case is naturally going to be stronger if there is an underlying crime that’s being prosecuted, said Ric Simmons, a professor at the Ohio State University Moritz College of Law.
It is "technically possible, but the legal and practical challenges in winning such an obstruction case would be great," Simmons said. "A prosecutor would have to prove that the president believed there was a collusion case ‘contemplated’ against him even when he did not engage in collusion. That is theoretically possible, but hard to prove to a jury."