In short: They're not. They're basically guessing at this point for anyone under 50.
Not only that but anyone under 50 who they do reach is the type of person who doesn't use an ad blocker. In other words, iPhone users and the ignorant.
I mean, even if they “reach” you doesn’t mean you have to pick up the phone or respond to texts. As a matter of policy I don’t answer calls from numbers not in my contacts. If it’s important they’ll leave a voicemail.
Weird clarification, but the iPhone has shitloads of adblock, much more so than Android. There are YouTube apps that block all video ads, for instance. iOS even has a vpn built into the OS.
The goal, as ever, is to present to the public an accurate reflection of what the people as a whole think about candidates and issues.
Can this not simply be harvested from the endless volumes of online posts made to the public internet? Why do they act like they need to go on the hunt for something that is normally difficult even to avoid?
The types of people that offer their political opinions online are not themselves representative of the whole voting public. This would introduce an instance of sampling bias.