Hundreds of thousands of canvassers and callers in the closing hours of the election—may look like the basic work of campaigns, the slog of door knocks and repetitive phone calls. But as is the case with much of Obama’s campaign, the dutiful fieldwork is undergirded by sophisticated analytics unmatched by his Republican opponents:

Obama’s databases already knew a lot about the approximately 180 million registered voters in the United States. The campaign's algorithms ran the numbers and predicted the likelihood that every voter in the country would cast a ballot, assigning each a turnout score. Obama's analysts knew how good their support score was because they polled a new group of voters to validate it: 87 percent of the time it would accurately predict an individual's preference.

The purpose of a GOTV canvass is to mobilize only those known or highly likely to be supporters. Read More