What you need to do is tell them you do not want to receive their calls, and make sure you do a opt out with all the political parties. Then, if you receive calls, go that persons web site and under their contact us page, write them and tell them to place you on their internal dnc list and also there is a political do not call you can sign up for. I did and also tell them to use that list and give them the url for it. I have not gotten any calls for years now. Not even political survey's. So it does help to follow the steps.
http://stoppoliticalcalls.org/index.php
The other thing that will help, if you have a cell phone, if it doesn't already have call blocking, there are free call blocking apps online you can get for some phones. If you have a land line, google call blocking devices. There are phones also available with call blocking but they do not hold as many numbers as devices do. Many of the devices run around 60.00