Two days after Election Day, it's still too close for CNN to project a winner in six states: Alaska, Arizona, Georgia, Nevada, North Carolina and Pennsylvania.
The process that goes into CNN projections is careful and complicated. It involves both real-time results and information from exit polls.
CNN, NBC, ABC and CBS work with the polling firm Edison Research in what is known as the National Election Pool for results and exit polling data. Fox News and the Associated Press have a separate arrangement.
CNN’s polling director Jennifer Agiesta explains more about this process:
There isn't any magic involved in projecting races, sadly, it's really all math. There are a number of things we are looking for in each state to have confidence in a projection. Most important is what's been counted: Where are the votes coming from geographically within the state, what types of votes are included in the count, and how much of the total vote does the count represent right now?
If there's a clear lead for one candidate in the current count, but none of the votes from the strongest part of the state for the trailing candidate aren't in yet, that margin likely won't hold up. If instead there is good geographic representation in the vote, that's a point in favor of a projection.
If everything that's been counted is absentee and early votes, or all Election Day votes, there won't be a clear picture of how all the votes will look when both types of vote are included. Some of both are needed for projections in closer races.