Robert Caro, in the LBJ series, wrote about how LBJ would use the discomfort of being the bathroom as a negotiating technique and a show of dominance. He would drag senators into the bathroom and force them to listen to him talk as he used the urinal, or force his staffers to take dictation as he took a shit.
It was somewhat of a joke;) He completed Kennedy's term and and was only only elected once. He refused to run for a 3rd. Given the immense ego's of these guys one might assume it was because he was unlikely to win. Peeing on people is unlikely to win you a lot of friends.