Have you ever lied to a pollster?
Okay, let's make a deal—I'll choose to believe you if you choose to believe me. And never mind the fact that anyone who would lie to a pollster might also lie about whether she had ever lied to a pollster.
Actually, I don't lie to pollsters. Suppose someone calls and wants to know my opinion on an issue—whether marijuana should be legalized, say, or whether the President is doing a good job. If I decide to answer the questions, I'll probably go ahead and tell them what I really think. That's assuming the caller is polite, the poll doesn't take too long, the questions appear reasonably unbiased, and I'm not in the middle of dinner.
For more specific questions, though, like which candidate I intend to vote for in a particular race, I generally decline to answer at all. For one thing, I tend to be suspicious about the impartiality of a great many polls. Framing questions so they are unbiased is incredibly difficult even if you're trying to be neutral—which, in my opinion, is often not the case. Maybe I'm just naturally contrary, but I prefer not to participate in what is essentially a marketing strategy for one candidate or another.
My second reason for not answering pollster's questions is, I hope, a bit more high-minded. One of the rights we have in this country is that of being able to vote in secret. I value the fact that no one, from an employer to a government official to my spouse, has the right to know how I vote unless I choose to tell them.
So why on earth should I share that information with some miscellaneous polling organization just because they happen to call and ask? If they want to find out how I'm going to vote, they can just wait until I get to the voting booth on Election Day.
After all, sometimes that's exactly what I do myself.