I decided to finally answer. The person asked if they were speaking to a male registered voter.  Since I am not male, I said no and told them I'd have to let them go. Forgot to tell them to please stop calling.

I left my number and last name, hope it works, i get 2 calls per day from them.
Info from their web site: Call 1-866-360-9563 from within North America or 1-801-379-4094 outside North America to be placed on our no-contact list.

Also, you can email them your opt-out request.
From their website:
Email us at optout@surveysampling.com and include your phone number in the body of the email.