Can modern politics avoid propaganda?

With the US presidential election on the horizon, to say nothing of a number of Australian elections, our airwaves, news sites and social media feeds are filled with political rhetoric. Many of us have come to accept political rhetoric — with its obfuscations, generalisations, exaggerations and outright evasions — as the price of doing business with democratic politics. Is there a meaningful difference anymore between political rhetoric and propaganda? What disciplines and constraints must political rhetoric adopt in order to keep itself free of the propagandistic temptation?