On MSNBC’s Morning Joe on Tuesday, host Joe Scarborough criticized Silver’s prediction, which now states Obama has a 79 percent chance of winning the election, higher than it sat earlier this week.

“Nate Silver says this is a 73.6 percent chance that the president is going to win?” Scarborough said. “Nobody in that campaign thinks they have a 73 percent chance—they think they have a 50.1 percent chance of winning. And you talk to the Romney people, it’s the same thing.”

Silver, apparently spurred by this criticism and others, made this wager to Scarborough on Twitter on Thursday: “If you think it’s a toss-up, let’s bet. If Obama wins, you donate $1,000 to the American Red Cross. If Romney wins, I do. Deal?”