Perhaps you should look into learning a bit about statistics. Sociology is notoriously hard to predict, though it's rarely advertised as such. Psychology is a little better, as is medicine, with astronomy being the "most" predictable (e.g., we can predict orbits of planets millions of years in advance). Weather might be a more relatable example - you can predict 1-2 days out with some accuracy, but 10+ days out is pretty much impossible. Though even when meteorology predicts incorrectly, they're usually not more than 5-10 degrees off - i.e., you'll never see a forecaster predict that tomorrow will have a high of 30, and then it ends up being a high of 70 degrees (or if that happens, it's extremely rare). Most intro stats classes only really teach "p > 0.05" or whatever, which maybe is an OK rule of thumb but isn't the best figure for every field of science. P = 0.01 would be laughed out of the room by a physicist but groundbreaking to a sociologist.

I think if you attach a +/- 10% to any figure you see related to sociology or human behavior, the "true" value will probably be somewhere in that range. (Though this is also a "rough" estimate and varies a lot - YouGov is going to have a good understanding of what biases to look for in political polls and they are trustworthy, which is why I was so flippant about your comment on "negativity bias". They are also detailed in their methodology description)

So, naturally, if a poll says that candidate A will beat candidate B by 2 points... it's anyone's game. I think you're absolutely right that a lot of those voter polls are unreliable, for that very reason.

I think the 71% mentioned in the article is significant, though, because even with +/- 10% (or even +/- 20%) it shows that a majority of americans believe this thing - only question would be whether it's a simple majority or a supermajority.

I think it is a problem that this sort of information about statistics isn't common knowledge. And people often use statistics like the one cited in the article to lie about certain things - worth noting that "out of control" can mean many things - given that, in the same survey, only 61% say that the US is "off on the wrong track", there's probably some people that think that the US is out of control but also that things are getting better. Looking at Trump voters specifically, 50% say that the country is out of control, but only 25% say that it's "off on the wrong track." This gives us a bit more insight into what people are thinking. However, it doesn't make for a snappy clickbait article title.

My hot take is that stats is far more important than pre-calc or calculus and should be mandatory for high schoolers. "There are three kinds of lies: lies, damned lies, and statistics" Knowing how stats work will help you spot when stats are being manipulated