On Wednesday, former Director of Data Science for the Romney campaign Alex Lundry and veteran Democratic strategist Tom Bonier discussed how campaigns use information to profile and target voters. Sasha Issenberg, political reporter and author of The Victory Lab: The Secret Science of Winning Campaigns, moderated the discussion.

The event kicked off with Bonier demonstrating the use of the Democratic National Committee’s online voter database by pulling up Donald Trump’s profile on the website. Bonier found records including the day Trump registered to vote, the number of primary elections he had voted in, and his personal phone number.

“Where do we think his phone number came from?” Issenberg asked. Bonier explained that the data was collected from different sources, including phone directories, consumer data, and companies who sell cell phone data.

“We actually have two different numbers here, one which would presumably be an office number…and another one here which is presumably more accurate. I would suggest people not call,” Bonier said.

“Unless you’re seeking vengeance on behalf of Lindsey Graham,” Issenberg joked.

Issenberg then asked Lundry, who most recently worked on Jeb Bush’s primary campaign, to explain the creation of statistical models used to predict how likely a voter was to support gun control or to identify as a progressive. Lundry said that the modeling process involves taking all known information about voters, including thousands of variables, and using algorithms to make an informed estimate about how a voter is going to vote, whether they will vote at all, and what issues are most important to them.

“The way I like to explain this is, it’s basically a very sophisticated form of stereotyping. All of us have had life experiences that sort of lead us to make guesses about who people are that we don’t know. You go into a coffee shop and maybe the person in front of you in line, you can look at the book they have with them, the way they’re dressed, the car they drove, and you can probably make some reasonable guess about who they voted for, just based on these kinds of signals that they’re throwing off,” Lundry said.

Lundry went on to address the concerns that the public may have about such intrusive data mining. “The format of the information we get is detailed enough to be helpful, but not so detailed as to be intrusive…. You may be flagged as having a technology interest because you subscribe to Wired magazine, but we don’t know that. You may have that flag because you have a Best Buy rewards card, but we don’t know that. We just know that you have this technology interest.”

Bonier then discussed some of the variables his firm, TargetSmart, used in making models, ranging from homeowners’ insurance to owning stocks to whether the person had traveled abroad in the last year. From his experience working for the Romney campaign, Lundry highlighted purchases from a Christian bookstore and having a hunting or fishing license as two vital predictors of Republican voters.

The discussion also looked toward the future and the possibility of using data from search engines and social media to target voters. “That’s really the next frontier and there are some not insignificant hurdles. There are sort of two phases to that. The first challenge is being able to take the findings, which are quite robust, where we really know a whole lot about most people… and the challenge is, from a digital perspective, then being able to find them online,” Bonier said.

Bonier also spoke on the difficulties of working with social media companies that want to guard their own data sources. “Facebook is not going to tell us everything they know about you. They wouldn’t give away their keys to the castle. So we work with third party intermediaries who can match the data from Facebook and our data and create handshakes so then our campaign can advertise directly.”

Issenberg concluded by asking Lundry and Bonier whether Edward Snowden and the domestic conversation around online privacy have shaped their work.

Lundry said that privacy and security have always guided their work and referenced his recent tenure with the Bush campaign. “We’ve always been very concerned about security and now we’re even more extremely concerned about it. On the Jeb Bush campaign, on the day we announced, we had North Korean hackers trying to get into our stuff.”

Issenberg responded, “Are they the ones that stole the winning strategy?”