The 538 project started out with what seemed like good intentions, but it has morphed into something that is not what it was originally sold as. Nate Silver does not have enough meaningful data to calculate meaningful statistical figures.
The polls that he is supposedly relying on don’t even exist in some cases or are months old. Also most Republicans do not participate in polls that they know are being commissioned by leftists.
The 538 project came to us courtesy of the guy who gave baseball WAR.
The fact is no matter how good your polling there's still an element of good luck.
If polls were accurate, they would all report the exact same numbers.
As I said, every election cycle, ONE pollster gets lucky.