This bit right here made me trust the article a LOT less. Poll responses on Gun Control are very highly dependent on wording and how much information is provided.
For instance, people might support "universal background checks", but oppose "you cannot legally loan a rifle to your brother for a hunting trip". Or they'll support "red flag laws", but balk at "laws that let police take anyone's guns on the basis of an anonymous complaint". Same policy, different presentation.
Another example in a different field is "how much should the rich pay in income taxes?", where people will answer "more than they are now" (instead of "less" or "the same") but if asked to pick a percentage they'll choose one lower than current rates.