The author is one of the world's experts on the Traveling Salesperson Problem (TSP). He has a new book on the TSP written for the general audience coming soon.
http://press.princeton.edu/titles/9531.html
I've always wondered about this sort of political touring - does it pay off in the polls? How many people see the politicians at a rally versus reading about them or seeing them on TV? Or is it that they get a lot of press from the tour? Or perhaps they meet people who become fired up to be their grassroots support?
I'm spitballing, but hopefully someone here has some data or knows a bit more about this?