Simply because he can't provide such data. You're welcome to provide such data (copy from his website) and I'll poke huge holes through it.
"When downloading the data from here you promise not to give this data to others. If they want to obtain the data, they may simply come to this web site and download it for themselves."
http://www.johnlott.org/cgi-bin/signup.cgi
Feel free.
You're welcome to replicate his data yourself. That of course shows all fifty states side by side, if it isn't fifty states it was cherry picked (according to you).
I mean why would I trust a guy who created fake profiles to praise his own book on Amazon...
Um.