Political party is fairly easy in the US via voter rolls for primary elections. Even if this list is held privately by the Party, they have an incentive to trade it for data about independent or undecided voters.
Views & opinions are likely from member lists of organizations like the NRA. Again, these organizations will trade their data for valuable data on other people whom they want to reach.
Relatives is pretty easy to figure out if you have address history over time. People who are related tend to share an address at one time or another. Relationship status is similar when a couple moves in together. Obviously, there are also marriage records.
Education history is often verifiable by employers, even outside the country.
>> yes, I know all of this information exists out there somewhere (resumes, mailing lists, social sites, whatever); my question is who is the first layer aggregating them from these sources.
Views & opinions are likely from member lists of organizations like the NRA. Again, these organizations will trade their data for valuable data on other people whom they want to reach.
Relatives is pretty easy to figure out if you have address history over time. People who are related tend to share an address at one time or another. Relationship status is similar when a couple moves in together. Obviously, there are also marriage records.
Education history is often verifiable by employers, even outside the country.