I don't know what Russian Hoax is....
There was an investigation into Russian election interference...
Trump admitted on national tv that he fired Comey because of the Russia Thingy..
"Trump said: “And, in fact, when I decided to just do it, I said to myself, I said: ‘You know, this
Russia thing with Trump and Russia is a made up story, it’s an excuse by the Democrats for having lost an election that they should’ve won.’”"
President admits the allegations of collusion between his advisers and Russian officials played into sacking of FBI director
www.theguardian.com
So he was firing the FBI director who was investigating Russian interference which was aided by Trump Campaign officals...
That is obstruction of justice. Trump could have said he fired him for no reason but he didn't...