I would imagine someone has said this, but Nate Silver didn’t predict that Obama would win reelection. He simply calculated his odds at roughly 92%. Your statement that Silver will eventually be wrong is false simply because he doesn’t claim either candidate will win. He simply reports the odds and the data. If Romney had won, he would have been “right” as well, because Romney had a very slim chance of winning according to the Fivethirtyeight model. Like he has said, he doesn’t predict the elections, he just reports the odds.