why did shakespeare use iambic pentameter for the dialogue of noble characters, while commoners often spoke in blank verse or prose?

is it "means of nourishment"

from the political point of view it could be said that the candidate   is an effective speaker because she takes a strong position on the issue. it is an open discussion but probably she is making a presentation and can choose which subjects she wants to address. she is very likely to attain her aim which is to convince voters to accept her proposal.