How many such forms have they filled out and received a form letter reply? Do they read it. How often does the form letter thank them for standing behind their "representative" in their support of the thing they are against? "I am filling out this petition in defiance of X". FORM LETTER: "Thank you for contacting your representative. It is good that you care about your community enough to get involved. You are truly a great citizen. I am so glad that you stand behind me in my support of X, and together we can make truly great things happen."
If they talk to anyone else that also "protested" and signed a petition they will see that person received the same letter. They move on, feeling as though their actions made a difference. They tell their neighbors "I complained about this to our representative! You should too! I even received a response back."
shudder