That the Bull Moose Party, Perot's Party, Wallace's run, and Nader's attempt with the Green's is ignored.
I of course understand why it is.
The fact that these positions are marginalized by their inability to draw enough popular support. Too extreme loses support.
Gov Ventura proved that third parties can succeed, but he then had to work very hard to get consensus on many issues in the state, and could not use any momentum to increase the number of third party reps around. Our friends in Minnesota doubtless have some interesting opinions on how effective his leadership was.
Maybe that is why the US is so good at the digital stuff: our political background sees very well in binary.