Not to say that everyone that votes for Trump is a Nazi, but we do know who the Nazis are voting for.
But how do you get their numbers? Just dial randomly and hang up if the person sounds Republican?
When you volunteer with a campaign, you don’t get the phone numbers and don’t use your actually cell phone. You use a dialer program where the campaign dials and connects you via your computer. So you click a button that says you are ready to do a call, the program then uses their phone system to dial someone in their system and it connects the call to you via your computer. The phone numbers come from wherever campaigns get their lists from.
When you register to vote here, you can have a party affiliation and can give them permission to contact you.
Sorry was implying they you provide the information. Also when you move you update your voter registration.
The dialer software connects to a database with a huge set of phone numbers organized in various ways. The calls are often narrowly targeted - sometimes you are calling to confirm attendance at an event, sometimes you are leaving a scripted message for numbers that are known to always go to voice mail. You don’t do any literal dialing, you press a “next call” button and wait for someone to answer.