The old saw "statistics lie, and liars statistic..." wait, that's not it, "fool me once....won't get fooled again"...mmm, overused and off kilter..... maybe.... "It's just 3dB error", e.g. off by half - that's it.
Polls are popular - search hard enough, you're bound to find one that supports your cause. And if not, you can always complain about accuracy, number of people, leading questions and push polls, land lines vs. mobile, etc. But whether pro or con, polls typically sample 1/1000th or less of the final population. I.e. "a spit in the ocean" in modern parlance.