Ad populum fallacy or appeal to popularity fallacy.
“I would love for the media to have a month without polls. What is the value of these polls? If I am making a decision about a candidate, I want to weigh their record. Do I care what my neighbor thinks, or the person next to me? I want to make an independent decision.” — Amy Goodman
The Ad Populum fallacy is a logical error where someone accepts something as true or legitimate simply because a lot of people accept or believe it. A common example is the Fox News defense. When someone criticizes Fox News, its defenders point to the network’s ratings — as if the criticism is invalid simply because a lot of people like or watch it. The number of people who believe something has nothing to do with whether what they believe is actually true.
(Side note: An easy way to dismantle the Fox News ratings defense is to point out that ABC, NBC, and CBS network news each draw around 20 million viewers, compared to Fox’s 2 million. Fox defenders typically subscribe to the theory that all media outside of Fox News is liberal. Well, if high ratings alone prove the legitimacy of a news network, then that means the so-called liberal media is legitimate — since network news has higher ratings than Fox on cable. They should recognize the flaw in their appeal to popularity when confronted with this.)
Think about how many people once believed the Sun revolved around the Earth, or that the Earth was flat. Are those ideas true simply because a lot of people believed them? At one time, people believed that a woman could not get pregnant if she was standing up. I can only imagine some of the interesting positions people had sex in, thinking pregnancy could be averted — only to end up with a child nine months later.
The truth is that the general public often supports and believes things they are not well informed about. When the Affordable Care Act was being debated, the “public option” was highly contested between the right and left. Supporters always pointed to polling data showing that the general public was highly supportive of the public option. But when those same polls asked the very people who supported it to explain what it was, they didn’t really understand it. That didn’t stop proponents from pointing to how popular it was.
In the case of Donald Trump, he uses the Fox News defense. He cites his polling numbers as a rebuttal to criticisms about his substance and his positions. Amy Goodman’s criticism of the media is that they constantly report on how popular each candidate is, instead of presenting their actual policies and positions to their viewing audience.
Further Reading:
Ad Populum Fallacy – Skeptics Dictionary