If asked, most people would say that Nate Silver had the most accurate prediction of the 2012 election, but that’s not true. Silver actually mis-predicted at least one Senate race. It was Sam Wang who was perfect in 2012. Wang is a neuroscientist at Princeton University and the head of the *Princeton Election Consortium*. He was one of the first people to aggregate election polling, starting back in 2004. And he currently gives the Democrats a 70% chance of holding onto the Senate.

This came as a bit of a shock to me. I’ve been following *538*, *The Upshot*, and *The Monkey Cage* models, and they all are very bullish on the Republicans taking control of the Senate. For example, *The Upshot* currently gives the Republicans a 65% chance. So what is going on?

The difference in the predictions is based upon the kind of models. Wang’s model is based entirely on polling data. As far as I know, *The Monkey Cage* is based entirely on fundamentals like the state of the economy. *The Upshot* and *538* models are a combination of the two. The truth is that the fundamentals suck for the Democrats. But as Wang noted today:

Of course, all of this could change. But the truth is that the election isn’t that far away: just over two months. One would think that if things were going to turn, they would have done so by now. But we haven’t seen any indication of that. But I know that I *what* to believe Wang’s results. Regardless, even his 70% Democratic probability result finds the most likely Senate makeup to be 50-50. The polls with the fundamentals have the Republicans controlling it 51-49. So the models are not all *that* different. It just shows that there is a lot of uncertainty. At this point, it doesn’t make much sense to get too excited or too depressed.

### Update (29 August 2014 4:24 pm)

I just checked, and The Monkey Page model that a month or two ago had the Senate going Republican with an 80% chance, now gives the Republicans only a 53% chance. FiveThirtyEight can’t seem to be bothered to update their model more than once a month. Daily Kos gives Republicans a 55% chance. It is only The Upshot that gives the Republicans a big chance: 65%. That’s interesting.