(I believe that term has been invoked in recent threads, along also with "narrative" as a form of rhetoric).
I believe the dictionary (or handbooks of composition) will list quite a few legitimate senses of the _word_ "rhetoric," and no one can fight against mere usage of a word.
But in this post I'm going to assume that in most, perhaps all, uses of the term (not just on this list but by, e.g., Kenneth Burke, Deirdre McCloskey, or Wayne Booth) its original senses still operate powerfully -- and all those original uses of the term (Aristotle, Cicero, Quintilian, Renaissance rhetoricians) make two assumptions: (a) that speaker (usually speaker, not writer) and listener (audience rather than readership) directly confront each other in a framework agreeable to both (e.g., a parliament) and (b) that there is _almost_ complete agreement on all the important issues between speaker and listener. The "almost" is of great importance, for the difference is of course the reason for speaking; but the "[nearly] complete agreement" is the context within which the persuasion proceeds. The whole of the art is directed to demonstrating that this large shared agreement dictates that the speaker's position on the small area of disagreement should prevail.
(This kind of rhetoric still exists today only in churches which put a great emphasis on sermonizing.)
Rhetoric is not only of little use to the left; attempts to develop a left rhetoric aid the right.
There are no "new ideas" here, incidentally. The ideas I'm opposing go back over two millenia. The ideas I'm proposing go back to the late 19th century (developed within the ranks of the German social democracy.)
The left (willy-nilly, incidentally, even when leftists think they are using a rhetoric) casts persuasive discourse under three headings officially, four in practice: theory, propaganda, agitation. The theory of all three is ill-developed (in part at least because of the freezing of leftist thought under the Third International), so there is plenty of room for fresh thought. Clearly factory gates can no longer be the favored locus of agitation, so it is particulary methods of agitation that needs most rethinking, but the deadend which leftist concern with rhetoric (as shown on this thread) constantly reaches is merely one indication of the need to carry on that fresh thought within the classical categories.
(The fourth is polemics -- for which there is very little theory to guide us, mostly because it was never recognized as a distinct genre of left writing and speaking, though it is one of the most often practiced.)
My contributions to lbo-talk are most frequently driven by concern over the utterly undeveloped theory of agitation in current left practice.
Carrol
P.S. These categories have nothing to do with "Leninism," though the most convenient source for a summary of 2d international thought on the subject is to be found in WITBD.