Opinion vs. Truth

After reading section 2 of RoM, I'm still a little confused as to the distinction Burke makes between opinion and truth. Burke writes,"the competitive and public ingredient in persuasion makes it particularly urgent that the rhetoric work at the level of opinion" (54). From this, I assume that Burke is getting at the need to understand other's opinions first if one wants to seek identification with his/her audience b/c w/out such identification, persuasion will be difficult to achieve. Anyway, what I'm interested in are the implications of moving to opinion first rather than truth. Specifically, when we move to opinion, we begin to delve into people's subjectivity rather than an objective truth from which to persuade from. I know I'm short-circuiting this discussion a bit by jumping to my question now, but in stressing the need for rhetoric to work at the level of opinion, does Burke open the door for rationality to be based in subjectivity rather than objectivity? Something I'm interested in is the idea of moving away from the modernist notion of objective/empirical truth and rationality and making room for the subjective and personal. Is Burke making room for this, and, though this is a broad generalization, is he denying the presence of an objective truth and arguing for a dialectically based truth? I don't like how I posed that question because we've read previous examples of Burke's discussion of dialectically based truth, but what are the implications of going to opinion first?