Understanding the difference between credible information and propaganda

In the context of my role as a teacher interested in encouraging my students to understand the difference between credible information and propaganda, this language from DonaldJTrump.com will make a good discussion topic.

I teach my journalism students to cover stories fairly. Journalists would not be doing their job if they simply repeated the results of this poll, without contextualizing the results via the input from an expert qualified to discuss the validity of the poll.