With frequency and precision, his analytics team delivered a picture of what was happening in each of the remaining states. They knew what the returns were showing, who voted from where and which votes were remaining.
As each night wore on, aides grew confounded. It was evident Donald Trump no longer had a path. Why was it taking so long to call the race?
"I was reading our analytics and seeing our comms shop express frustration that all of the data was on our side and all of the networks agreed, but they were too scared to call it," said Biden campaign co-chair and Rep. Cedric Richmond (D-La).
On Friday, when Biden took the lead in both Pennsylvania and Georgia, several aides said they had never felt such jubilation. Nevada was also clearly headed in Biden's favor.
And yet again, all day, there would be no call.