So Trump is investigated by the FBI for obstruction of justice, they find evidence of his crime and say "Trump is not exonerated".
They then give the decision to prosecute over to Barr, who wrote a 19 page opinion piece on how a sitting president cannot be guilty of obstruction of justice, and Barr decides not to prosecute.
Trump supporters see this as a good thing. Trump supporters are fucking idiots
Now congress takes up the obstruction charge getting all the info/evidence from Mueller, starting with the House.