Allan Lichtman asserts that his 13 Keys system is robust because it is based on 160 years of history and should not be modified to account for unprecedented contemporary events.

“I'm not so arrogant as to say it's impossible that there could be some unprecedented cataclysmic change to shift the pattern of our politics the problem is you can never know that just like a scientific revolution can't predict it in advance you can only know it after it has occurred that's why I do”