You may recall a political dust-up this summer when the Clinton campaign accused the Sanders campaign of gaining illicit access to its voter data. How was this even possible? Well, it all traces back to a private company called NGP VAN. This article was first published on the Infocommerce Group Blog.

NGP VAN, which works only with Democratic and progressive candidates for office, maintains a central national voter database that it regularly updates and enhances. Providing campaigns with conve...