I think this is an assumption. Sure, I already pointed this out. But the key takeaway is no matter how you phrase it (without actively trying to spin the poll), you get a clear majority wanting increased background checks. Fairly unambiguous, but if you drill down: Still a clear majority. And this doesn't even speak to gun shows. This involves two private citizens making a sale to each other. People aren't misunderstanding the question here. This isn't that tricky. The poll isn't asking if people think that it will solve a serious problem. Part of the reason this might enjoy such large support is because people perceive it as a small "no-brainer" that might only chip away but should be done nonetheless. That's a guess like your guess. What we do know is that people favor some form of increased gun control. Overwhelmingly.So the reason those polls are ambiguous is that people think (a) it's a serious problem that will (b) make a difference.
If you phrased it differently you'd get a different answer.
• Quinnipiac University poll, March 26-April 1, 2013. "Do you support or oppose requiring background checks for all gun buyers?" Support: 91 percent. Oppose: 8 percent.
"If the buyer is trying to purchase a gun from another person who is not a gun dealer but owns one or more guns and wants to sell one of them." Favor: 70 percent. Oppose: 29 percent.
Huh, I had not seen that second one. That first one is completely useless. Is it asked before the second one? I am always reminded of the "Ban Bi-Hydrogen Oxide" stuff. Side note: it's not increased gun control, it's control of the transfer process. -XC