It's worth noting that Lichtman's predictions use very different methods than pollsters and data-based prognosticators. Some statisticians take issue with the structure of his system, a set of 13 true/false questions, saying that the binary nature of his keys leads to what's called "overfitting," which is basically creating a system that fits the data but has little statistical significance. But Lichtman counters by saying that system has correctly predicted every election since 1984 (specifically, his predictions have picked the next president correctly in all of those elections but 2000, when he picked Al Gore, who won the popular vote). And Lichtman has his own criticism for data-based predictions.