One of the tactics of the vocal opposition is a petition, a weapon I have said for decades is the least useful and most easily corruptible method of public “input” there is. I’ve personally experienced the tool being abused many times. The problem is, project opposers use petitions as a tactic because the media loves to report on them, and politicians give them weight even when they shouldn’t.
- Brent Toderian
Petitions aren't representative. They aren't a sample. They are the reverse of a sample, merely an indicator of how many people you can get to sign a piece of paper. And without a context of magnitude that is normal for a petition, it's hard to tell if 100 represents a lot of people or mere crankery. Again demonstrating the value of an actual (statistically valid) survey for assessing public opinion on a topic.
I understand that surveys are expensive (to design, to administer, to analyze) and that they are addictive. But they do offer elected officials something they can't get elsewhere: A representative sample of what their voters actually think on a specific issue.