On: Ask HN: How do news networks get election data?

[pionar]

Exit polling is different than the results the OP was asking about. The exit polls last night were wrong, they were predicting a Clinton win.

See others for what actually happens. There's reporters sitting at county clerk offices.

[camiller → pionar]

Yeah, but the OP was also asking about demographics. The county clerks are not the source of that information because it is not collected on the ballots. The only source of that information is exit polls.