“59% of voters oppose building President Trump’s long-promised wall along the southern border, and only 37% support the measure, according to the Quinnipiac poll.”*
“79% of Americans expect that if a wall is built along the border, the U.S. will ultimately pay for it. Just 14% expect Mexico will pay, as Mr. Trump has claimed. 60% of Republicans, and 91% of Democrats, think the U.S. will pay for the wall if it is built.”*
“The majority of Americans (57%) oppose expanding the construction of walls along the nation’s Southern border, a centerpiece of President Donald Trump’s proposed immigration-related policies.”
“83% approve of allowing DACA immigrants to become citizens.”*
“I will take the mantle. I will be the one to shut it down. I’m not going to blame you for it.”
—Trump to Nancy Pelosi and Chuck Schumer, December 11th, 2018*
Since you post polls regularly, could you explain how these polls get these conclusions? Because I certainly have never had the opportunity to put in my vote. So I am curious how they are a reliable source of information and why they are used to calculate how many Americans think this or that.
TJ, a fundamental concept in statistics is the central limit theorem. It shows that one does not have to poll 100% of people to get a generalizable result.
The better and larger the sample, the better the results typically are. But if you’ve got a demographically representative swath of a given population, you should only need to get 20-30 responses for those to be highly representative of the overall population. So, 1,520 would be enough to get about 30 responses per state. (Though, there probably would be more responses gathered from states like CA, TX, and NY).
Polling orgs don’t generally say stuff like, “69% of those polled.” They don’t make polls like when you poll your friends. They’re trying to get a representative result to extrapolate to a general population. If you poll your coworkers about what they think of building a wall along the southern border, this is called a “convenience sample” and will be worthless in telling us what people in the US think overall. It will simply tell us what your coworkers, who probably live in a single metro area of Florida, think. That could be great for figuring out where to have a company picnic (assuming you get a good sample) but is worthless for determining federal policy.
Polling can be difficult, and some organizations do it better than others. The polls I cited are from Quinnipiac, CBS/SSRS, and Gallup. These are among the best polling organizations currently around.
How do we know that one is more reliable than another? One way is that, when these organizations poll people before elections, we can see how much the election results conform to their polls.