I too have been getting calls constantly from these people. I would answer and they would hang up I used to answer and leave it by the TV.
I called then finally to confront them, I did not really expect an answer but they explained that they are a service for collecting donations for certain political groups. The recording then asks if you want you number removed from further calls. All you have to do is enter your phone number and they tell you that you will no longer get calls but you have to wait 48 hours for the system to realize this...