I think it’s a “cohort” thing.
Those in my cohort will all be voting — against Hillary. Whatever that means.
Your mileage may vary.
And there will be strongly D cohorts that will experience less enthusiasm to vote for Hillary than they had in 2008 and 2012 to vote for the halfrican.
Personally, I think that the momentum and enthusiasm shift from D (less enthusiasm) to R (more enthusiasm) will be a huge outcome driver in 2016.
Just my 2c.
It means they'll vote for Hillary's opponent no matter how liberal the opponent is, or no matter how much the reality is that if what they vote for wins they will protest against its implementation if it wins, even though they helped it win.
Adopting the sophistry of voting "against" allows for the same out I used to give myself -- they didn't vote for all that leftist crap, they voted "against" the scariest official Democrat leftist.
Ask any conservative who voted for Romney in 2012. They didn't vote for Romney, how dare I say such a thing! They voted against Obama!!!
Here is "what it means." Those who vote "against" Hillary want not to be accountable for what they're voting for.
My tagline took many years to learn. It's truth.