There is an intricate and intractable relationship between the three foremost modes of discourse – grammar, logic, rhetoric – which comprised the teaching of language in the Middle Ages – taught for a thousand years as the “Trivium.” Grammar, logic, and rhetoric have all changed over the years – as they must – but I think the Medieval teachers better understood what we need to learn about language practices than we do today. At any rate, a good theorist or critic of rhetoric, to be such, must be well schooled in the Trivium – must be aware of logic and grammar, to recognize how these are used rhetorically. It should also be noted that in evolutionary terms, grammar is probably primary, since without order language cannot be understood, rhetoric is secondary, since the principle function of language is agreement on action between people, and logic tertiary, as a clarification of rhetorical and grammatical protocols. But I admit I am now wandering into speculations on the origins of language, which can only be the subject of speculation, since we have little evidence on the matter.
The following develops from responses to an article by Dwayne Holmes, “No Contest,” which attempted to refute understanding of rhetoric as a proper heuristic for deployment in either understanding or enacting political discourse.  It deployed two primary arguments: The first is that rhetoric, as the art of persuasion as such, is too dangerous to be allowed unconstrained in public argumentation, which ought to proceed to judgments derived logically. The second is that rhetorical criticism is useless for understanding the public presentations of the current President, Trump, since he makes no argument and is no master of rhetoric; intead, it is asserted, he is merely a dishonest entertainer, and only has followers seeking to be entertained rather than deal with issues of policy.
What we’re supposed to see from the conjunction of these arguments is how powerless an understanding of rhetoric is in dealing with political discourse, since the real tension there is not between rhetoric and logic, but between ‘serious’ political engagement (necessitating logic) and political ignorance.
However, this doesn’t make any sense, because it leaves us with a lack of explanation of the Trump phenomenon such that we can develop strategies of persuasion for those who follow him. This would necessitate a broader, deeper appreciation of how people make political judgments based on emotionally informed motivations and not simply rational self-interest, which thus also necessitates a broader, deeper understanding of the art of persuasion that must address these motivations. So what we really find is that failure to understand the full dimensions of rhetorical practice leaves one powerless before phenomena that seem to involve irrational judgments based on criteria other than the logically feasible.
The two arguments do not hold together in such a way that a conclusion follows logically from their premises; and the premises lack properly convincing definitions their of terms. It is not surprising then, that the essay ends, not with a summary restatement of the argument(s) and their logically derived conclusion, but with the rhetoric of an emotionally charged promise that the future will somehow make all such matters clear.
Let’s consider Holmes’ issues from a different perspective.
Journalist Anthony Zurcher, remarking Donald Trump’s rhetoric: “He pulled back the curtain on the show and laughed along with his supporters at the spectacle. He encouraged his crowds to cheer the hero (him) and berate the villains (everyone else).” That’s an appeal to an audience. It is persuading that audience to respond in a certain way. That is what rhetoric is supposed to do. 
‘Vote for me because…’ is quite obviously the initiation of an argument during an electoral process. One may say, the election is over; however, Trump is already currently engaged in a campaign for re-election in 2020. Therefore, he is still making that argument. (There are several other more discrete arguments he is making, concerning the nature of the media, the right of a president to do as he pleases – thus the very structure of American government, the nature of American society, and the nature of foreign affairs. But his argument for re-election is the most obvious. )
Some would deny that Trump is making any arguments or using any rhetoric, insisting that Trump is involved in distractions rather than persuasions; but as I showed with the Zurcher quote, this won’t do. It is true that Trump is not reaching out beyond his base, but his rhetoric is quite successful in keeping his base committed to him.
While I personally think the Electoral College is an outdated institution, it remains a hard fact of American politics, and needs to be addressed in political strategy and should help guide the rhetoric of a national campaign. Clinton didn’t plan on this, relying on a “Blue Wall” of reliable states that didn’t really exist. The Republicans understood this full well, and reaped the rewards of their strategy and the rhetoric used, including that by Trump.
One might wish politics would be entirely reasonable and orderly. So did Socrates – that ended in his drinking hemlock. As I’ve remarked elsewhere, politics is war by another means, not the other way around. It’s a dirty business, and those who don’t like the dirt should not play. If Democrats keep insisting that ‘the other side’ play fair, instead of coming up with a more persuasive politics, they will keep losing elections.
I suppose one might look forward to things getting worse to the point that everyone awakens to realize the rightness of the liberal point of view (and act accordingly). There are two things wrong with this: 1, no matter how bad things get, they can *always* get worse; and humans simply learn to adapt. Because of this, 2, such a hope is doomed to disappointment – Marxists believing this have been disappointed time and again; social critics in ancient Rome were disappointed to the point of the collapse of the Western Empire, after which there was nothing left to hope for.
There certainly is an ethics of the practice of rhetoric, and this is discussed within rhetorical theory; but ultimately this depends on a more general ethics per se. The fundamental criteria of a successful rhetoric is that it works. When to use it, whether or not to use it, how best to maneuver between different modes of discourse and in the service of what causes, is entirely a matter of practical ethics and (in the present context) practical politics.
I’m not a cynic, but I am a pessimist. That’s because I accept people pretty much as they are, rather than how I think they should be. Most people – yes, even most Trump voters – hold themselves up to pretty high standards – they may not be my standards, and I understand frustration with that – but they are standards, nonetheless, and people try to live up to them. When they fail to do so, it’s not because they’ve been manipulated by swindlers, but because uncertainty leads them to misjudgments – they are trying to do their best, but are unsure of what the best might be in a situation of insecurity. Some want them to adopt other standards, and, further, to discuss those standards only in reasonable argument, and, finally, only act according to a reasonable conviction reached through those arguments. This is not addressing human beings.
In real politics, there is a necessity for addressing all the perceived needs of the electorate, and not just their ‘best interest’ as decided by experts.
That politics is war by other means – this derived from Hobbes, not Machiavelli – is certainly pessimistic, but it stands on solid ground: History demonstrates time and again that when politics breaks down, war results. Perhaps it is this inevitable trajectory that politics is intended to stave off.
I said that the Western Empire collapsed, and it was the Western Empire that social critics in the Late Empire were concerned with preserving. Eventually the City was abandoned, and civilization moved elsewhere. In the West, by the way, this meant the conquering of hearts by way of an utterly irrational promise that the life after death would resolve all the dilemmas of the earthly struggle to survive, delivered through a militant organization drenched in mystery and armed with paradoxical faith in what could not be ‘proven’ but only believed. – exactly because it could not be ‘proven,’ and thus ‘must’ be believed.
 https://www.bbc.com/news/world-us-canada-40475448 – Or consider the analysis of Trump’s use of hyperbole by Joseph Romm. Also not a professionally trained rhetorician, yet Romm has earned ‘street cred’ in the field after years of experience negotiation public policy and authoring a book advocating the use of rhetoric. https://thinkprogress.org/donald-trump-may-sound-like-a-clown-but-he-is-a-rhetoric-pro-like-cicero-ac40fd1cda79
 And given this, by the end of this year, there should be at least two Democratic candidates running for the 2020 nomination. However, this is unlikely, because the DNC, which should be fostering new talent in such efforts, remains convinced that their glory days were the Clinton Administration, and that people will just get so appalled by Trumps antics… like hoping that the Republican Congress, knowing that Trump will sign any bill they can get onto his desk, would consider impeaching him.