Here's an SAT analogy question for you: Barack Obama's 2008 campaign IS TO race as Hillary Clinton's 2016 campaign IS TO _______. If you said "gender," you're only half right.
I'll get to what I mean in a moment, but this is something Isaac Chotiner raises today at The New Republic: in 2016, we'll get into a similar dynamic we see now, in which "the attacks on Clinton will be seen as sexist by liberals, which in turn will lead to conservatives feeling falsely accused of sexism. You can count on MSNBC, for example, to turn nearly every attack on Clinton into an attack on Republicans for hating women."
It's true that there will be an extraordinary amount of sexism directed at Clinton, just as there always has been. But unlike Barack Obama, who spent years planning how to make white people comfortable with his race (which worked for a while, until his victory became a real possibility), Clinton has never tried to make her gender unthreatening. I suppose we could mention the way she stepped back from policy and did more traditional First Lady stuff after the Clinton health care plan failed in 1994, but that was a brief interregnum between times when she in effect told the country that she was going to be just as smart and knowledgeable and ambitious as a man in her position, and if they didn't like that, then it was their problem and not hers.
The other thing that's different is the way people, and particularly conservatives, talk about gender versus the way they talk about race. To put it simply, a lot of conservatives are still unashamedly sexist. When MSNBC calls out Rush Limbaugh for saying something sexist about Clinton, he doesn't try to convince people that it's a calumnious charge and he is in fact deeply committed to gender equality. He doesn't much care, and neither do a lot of other people.
To what degree that ends up working in Clinton's favor politically, we'll have to see. Race both helped and hurt Obama (researchers are still sorting through which way the scales tipped on net), and on first blush something similar is likely to happen with Clinton: there will be people who won't vote for a woman, and there will be people excited about voting for the first woman president. There will also be women who are so disgusted by the misogynistic attacks on her that it pushes them toward voting for her.
But there is going to be absolutely no subtlety in the sexist attacks on Hillary Clinton, and the people making them will barely attempt to argue that they aren't being sexist. Instead of "How dare you call me that!" their response to the accusation will be more along the lines of, "Shut yer trap, girlie!"