As I cannot merely focus on only one presidential candidates rhetorical successes/failures, I can try and narrow them down. Most candidates have rhetorical success during the trial of their campaign; and fail not only once they make it to the primaries, but if they are elected. It is easy to lose sight of what one was put into the office for in the first place, so they seem to become like "every other president". They are unoriginal--or uninventive. They find ways to scrape up what the last president did wrong, and spend all of their presidency doing that. They are uninventive because they find ways to pick at the opposite party, because they let the people down--like every other president, and lastly, they are uninventive because they are listening to others.
I think that most do not have a problem with delivery, but a problem with executing delivery. They have a problem with telling the peoples one thing, and doing another. This is something every political representative struggles with, whether we like them or not. The exigence is simply the unimaginative minds of candidates that we put our faith into. When one is elected, they are the inventive minds we look to go to when we need a change. That takes us to the audience. We are the audience of any and every presidential candidate. No matter what happens, they work to please us. There have been many times Trump says something inappropriate, which then leads to backlash from the media and the peoples. That is not a success in a campaign because that shines a negative light in what he stands for. He tends to misunderstand the exigence--or the real world problems. Not the problems that he comes up with in his head for personal expression. The constraints are that once we get these political figures in office, there is no way of getting them out (unless you're Monica Lewinsky). This is why it is important to not only practice rhetoric, but practice it until you become a professional rhetor. Every single candidate has either had a problem with interpreting the rhetorical situation, lack inventiveness and creativity, or simply lashes out and says something inappropriate to the people. Very few have success with the rhetorical situation.
I think this is something that is important for most to look out for when watching the upcoming debates. It is not always noticeable when watching because we simply do not look out for the candidates using rhetorical situations, therefore, it does not cross our minds. But, most candidates do not address current problems or resolutions, they simply speak out of anger and power. Since this is an important year politically, focusing on little things like this can show you a lot about who you could be potentially voting for. The rhetorical situation is not merely used as a form of written communication, but oral communication as well.