"Why would anybody in their right mind vote for Hillary Clinton?"
Many, perhaps most, don't vote 'for' anyone, they vote against.
And all the republican candidates warrant being voted against.
Indeed, why would anyone vote for the likes of Trump, Cruz, Rubio, or Bush – that's the real question.
It's about the lesser of two evils – always has been, always will be; so one can vote against the greater evil, cast a 'protest vote,' or stay at home.
so you know hillary is evil
interesting and telling
There are also many, perhaps most, voters who see beyond the individual himself or herself running for president; who have a comprehensive understanding of what the presidency is, how it functions, and the role the Executive branch plays in the context of the Federal government.
One is not voting solely for the individual candidate, one is also voting for who will make up the president's cabinet, who the scores of administrators will be to implement the laws and determine public policy – and one is most importantly voting for judges appointed to the Federal courts and justices to the Supreme court.
When one perceives the presidency accurately in its full context, the importance of keeping a republican out of the WH come 2017 becomes crystal clear.