It is rare for two candidates to run against each other more than once , and the circumstances and therefore probability change each time . So who could ever prove me wrong ? Yes , I simplified the situation to make the correct answer more obvious . I assure you , though , that the answer in that simple situation generalizes . If Nate Silver assigns 7030 probability splits to ten elections in a row , then he ' s doing better if 3 of them go to the 30 then he is all ten of them go the 70 . And if accurately predicting each state in 2012 is a measure of Silver ' s model ' s success , then is his map for 2016 not an indication of failure ? Unless there are multiple states that he assigned a very high probability of voting for Clinton that actually voted for Trump , no , it ' s not .