ahead of tonight's final debate, donald trump throwing a hail mary. going after washington and intensifying his unfounded claim that the election is rigged. >> they even want to try and rig the election at the polling booths. >> reporter: even calling on his supporters to monitor polling places. >> people are going to be watching on november 8th. >> reporter: and doubling down on his media conspiracy theories. >> there's voter fraud with the media because say so poison the mind of people by writing false stories. >> reporter: the gop nominee pledging to shakeup washington. >> it is time to drain the swamp. >> reporter: now promising if elected he will push for term limits for members of congress. a populous proposal that has yet to succeed. >> decades of political failure and special interest collusion must and will finally come to an end. >> reporter: trump opting not to respond to president obama, who ridiculed the billionaire's