POLLING vs VOTING
The truth is that many people believe lying to pollsters is fair play. Political polling is a lot like the odds on racehorses.
Sometimes, it is more accurate than other times, but it helps if you buy a ticket to win, place, or show. In politics, it is all about winning. I do not have verifiable statistics, but I have sufficient anecdotal knowledge to believe that many people routinely lie to any pollster they encounter if they think it will help the viability of their candidate.