A question of (senatorial) surveys

AS a member of the academe, I look at surveys as an invaluable source of (primary) data for research. I have used surveys in a few of my journal articles.

Unless there is incontrovertible evidence that a scientific survey has been manipulated or distorted, or has used flawed methodology, then I stand by the integrity of the surveys. However, I do have several questions for one senatorial survey results released by a reputable firm recently.