I recently received a voter questionnaire from one of the politicians that represent me. (He represents such a huge number of other people that my level of insignificance would be difficult to calculate.) I usually just chuck these things in the recycling bin.
For starters, these questionnaires are not actually meant to provide useful feedback to the politician. They are filled with leading questions designed to elicit certain responses. These mailers amount to little more than campaign literature.
By sending out voter questionnaires, the politician hopes to get you thinking that he is the right guy to represent you. He is hoping to increase the chances that you will vote for him. He does not actually expect to derive any kind of guidance from this process.
Any response to these mailers is a bonus. The politician uses these responses for campaign purposes and as backup for positions he has already taken. I'm sure that almost all politicians will say, dripping with sincerity, that they honestly consider all feedback from their questionnaires. If you buy this shtick, you are worthy of being the pawn they hope you to be.
To be frank, filling out and returning a political mailer with the idea that it will actually influence a politician is ridiculous. Except perhaps at the very lowest local levels, the politicians that represent you have already made up their minds on most issues, having been influenced by professional and semi-professional lobbyists.
Your response will not change what a politician does. It may change what he says about what he does, but it won't change what he does—the deals he makes and the votes he casts.
In case you haven't noticed, I am rather cynical about politics and politicians. Many of our nation's founders felt that politics was a necessary evil—a nasty tool that was needed to achieve good republican government that hoped to balance the rights of the minority and the majority with some level of success
The political system was needed to pit the forces of ambition and avarice against each other for the good of all. But like all dangerous tools, it was meant to be used with great care and with proper safeguards in place.
Throughout the years, some have sought (sometimes successfully) to remove political safeguards because they are so darn inconvenient and prevent "us" from "getting anything done." A whole class of people has emerged that has, in effect, turned politics into their personal religion. They seek to expand its grasp and power with a zeal rarely seen in modern Western religionists.
Politicians may be needed to achieve what our Founders called "good government." But that doesn't mean that I have to like it or that I have to make the pursuit of their craft easier.