How Political Campaigns Use Your Data to Target You

Data about potential voters—who they are, where they are, and how to reach them—is an extremely valuable commodity during an election year. And while the right to a secret ballot is a cornerstone of the democratic process, your personal information is gathered, used, and sold along the way. It's not possible to fully shield yourself from all this data processing, but you can take steps to at least minimize and understand it.

Political campaigns use the same invasive tricks that behavioral ads do—pulling in data from a variety of sources online to create a profile—so they can target you. Your digital trail is a critical tool for campaigns, but the process starts in the real world, where longstanding techniques to collect data about you can be useful indicators of how you'll vote. This starts with voter records.

Your IRL Voting Trail Is Still Valuable

Politicians have long had access to public data, like voter registration, party registration, address, and participation information (whether or not a voter voted, not who they voted for). Online access to such records has made them easier to get in some states, with unintended consequences, like doxing.

Campaigns can purchase this voter information from most states. These records provide a rough idea of whether that person will vote or not, and—if they're registered to a particular party—who they might lean toward voting for. Campaigns use this to put every voter into broad categories, like "supporter," "non-supporter," or "undecided." Campaigns gather such information at in-person events, too, like door-knocking and rallies, where you might sign up for emails or phone calls.

Campaigns also share information about you with other campaigns, so if you register with a candidate one year, it's likely that information goes to another in the future. For example, the website for Adam’s Schiff’s campaign to serve as U.S. Senator from California has a privacy policy with this line under “Sharing of Information”:

With organizations, candidates, campaigns, groups, or causes that we believe have similar political viewpoints, principles, or objectives or share similar goals and with organizations that facilitate communications and information sharing among such groups

Similar language can be found on other campaign sites, including those for Elizabeth Warren and Ted Cruz. These candidate lists are valuable, and are often shared within the national party. In 2017, the Hillary Clinton campaign gave its email list to the Democratic National Committee, a contribution valued at $3.5 million.

If you live in a state with citizen initiative ballot measures, data collected from signature sheets might be shared or used as well. Signing a petition doesn't necessarily mean you support the proposed ballot measure—it's just saying you think it deserves to be put on the ballot. But in most states, these signature pages will remain a part of the public record, and the information you provide may get used for mailings or other targeted political ads. 

How Those Voter Records, and Much More, Lead to Targeted Digital Ads

All that real world information is just one part of the puzzle these days. Political campaigns tap into the same intrusive adtech tracking systems used to deliver online behavioral ads. We saw a glimpse into how this worked after the Cambridge Analytica scandal, and the system has only grown since then.

Specific details are often a mystery, as a political advertising profile may be created by combining disparate information—from consumer scoring data brokers like Acxiom or Experian, smartphone data, and publicly available voter information—into a jumble of data points that’s