Perot got 18.9% of the popular vote in 1992. Gonna be tough to beat.
https://en.wikipedia.org/wiki/United_States_presidential_ele...
https://en.wikipedia.org/wiki/United_States_presidential_ele...
As long as the majority of voters think of Trump as a broke racist narcissist and Clinton as an apathetic or unethical elitist he may well have a chance.
http://heatst.com/politics/gary-johnsons-polling-numbers-rea...
But no, the 13% was one poll's result for Johnson's general support, not simply a favorable demographic for him.
It's the young and economically squeezed vote you need to keep track of, both on the right and left. Trump and Sanders both knew this.