Speaking as a professional purveyor of "alternative facts"...
That's really what a magician is; someone who creates an alternate set of facts... at least temporarily. The difference is that the audience knows — or at least is supposed to know — where the alternative facts live and is able to leave them behind at the door. While I joke during one of the demonstrations in my show about setting up a member of the audience to start their own religion, even going so far as to suggest the rest of the audience prepare to tithe, the donations are never forthcoming. (And that's a good thing.)
The question remains, then, why are we good at identifying alternative facts only some of the time?
Recently, Business Insider offered an insightful look at why we have such a hard time purging misinformation from the public consciousness:
They identify a very real psychological phenomenon called the backfire effect:
It's a serious problem that does not admit of an obvious solution? How do you change someone's mind? It's a bootstrapping problem, eloquently described by Sam Harris:
What has become very clear to me over the past year or two, is the solution is not to cut off contact with these people. We read often that the way you deal with a T***** or Milo Yiannopoulos supporter in your Facebook feed is to unfriend them. While that spares you the unpleasantness of having to notice whatever they post, you also take yourself out of their feed and reduces the chances they will encounter viewpoints contrary to their own and have to deal with the cognitive dissonance. A similar strategy is observable on college campuses where student groups will try to have speakers they disagree with disinvited. (The trendy term is "deplatforming".)
What these approaches fail to recognize is that humans rarely change their minds quickly. The Apostle-Paul-style Road-to-Damascus conversions where a lightswitch gets flipped in the brain and you fall to your knees are the exception rather than the norm. Even in science where rationality is supposed to rule the day they still have the expression that "Science advances one funeral at a time." You have to let the new information sink in gradually and stew for an extended period. And to leave people in the dust when that process has just started is unhelpful.
So part of the responsibility is on the reasonable people to tough it out and endure the misinformation, offering polite and well-sourced corrections rather than reaching for the block button.