On Monday, Britain’s Channel 4 News revealed that the 2016 Trump campaign targeted individual black voters with social media ads intended to keep them away from the polls.

A cache of data used by the campaign’s digital operation shows that 3.5 million black voters were lumped into a category marked “deterrence,” designating people the campaign sought to dissuade from voting. Black people were enormously overrepresented in this “deterrence” group according to an analysis performed by Channel 4.

Trump’s digital campaign strategy relied heavily on data mining, which allowed it to target ads to particular individuals based on information gathered by Facebook, as is now well known. But while the method was disturbingly precise, the principle is familiar. Campaigns tailor ads to specific demographics all the time. And since Republicans know they have little hope of winning most black voters, they run negative ads designed to kill enthusiasm among black people for Democratic candidates instead, hoping even a small dip in black voter turnout could help Republicans in battleground states.