"People had a preexisting mental notion of what a female candidate would look like, and she doesn't look like it. She is being penalized for having a series of traits that people find unacceptable in a woman."

"She's a woman," the best-selling author and staff writer for The New Yorker explains.

Hillary Clinton's unpopularity boils down to one issue, journalist Malcolm Gladwell says in an interview with CBC News : Sexism.

Specifically, Clinton is being penalized for her ambition, Gladwell says. It's a trait that women in leadership positions "are not allowed to have," he explains.

"She doesn't try and hide her desire for power under her hat, and we continue to expect that women have a kind of modesty in positions of authority. It makes it easier for us to accept the fact that they have moved into a man's realm."

Consequently, Clinton is deeply disliked — and has been, much of her time in the spotlight, even before the recent email and Benghazi scandals, Gladwell notes.

"The United States is a good deal less open to women in positions of power than it would like to pretend that it is," he says.

We'll see just how open — or not — the country is tonight.