Those numbers for Clinton are absolutely abysmal.
Democrats in a state like Wyoming tend to be solidly Democrat since they are so outnumbered, so this tells me there is a significant number of Millennial/Bernie type holdouts to explain only 19% support for Clinton.
Unless you actually like the party's nominee, I never understood the urgency of voting for that person if you don't live in a swing state. If I were registered to vote in California instead of back home, I'd definitely vote Darryl Castle.
So it makes sense young Wyoming Dems aren't too interested in a meaningless vote for Hillary.
