I don't imagine a clear divide between 'rational' and 'irrational' betting (for want of a better description), I'm just saying that I would expect there to be a lot of both going on.

If you're wondering why I believe this, the book 'Predictably Irrational' by Dan Ariely springs to mind as a good read about the subject. Also 'The Tiger That Isn't' (Michael Blastland/Andrew Dilnot), not about human rationality as such but rather, how easily we can be foxed by information depending upon how it is presented to us (in the context of 'reasoning poorly' about the election).