The Congress would not know "collusion" or "obstruction of justice" if it hit them in the face...

Trump has been obstructing this investigation since Day 1. He fired the FBI Director. He enlisted House members to lie to the press. He tried to get FBI Director to drop investigation on General Flynn. He tried to fire or discredit anyone and everyone at the FBI who might have disagreed with him. He tweeted derogatory remarks about everyone involved with the investigation. He admitted on nationwide TV that he fired Comey so the Russia investigation could end. He met with Russian officials in the White House with Russian reporters, but no American press was allowed, and bragged about how he had gotten rid of the nut at the FBI. But there was "no collusion" There was "no collusion", he continued to insist.

But everybody had seen collusion and obstruction with their own eyes. Why do they still pretend there is no proof of obstruction or collusion, when there is a ton of proof, in the public domain??