The elements of Sexual Misbehavior and promiscuous activity is accelerated and nitro fueled in a college town. Think of Fraternity houses for a second and think back to college parties you have seen. The elements are stacked against both Male and Female for something to go down in a negative way. However, that does not make it right just because they are in college experimenting. I think between 5-10% of that number feel remorseful guilt and are looking for a way out of a shameful situation. Their are some sexual predators lurking on college campuses though.
I'd say within the years of higher education, at least 1 in 5 women would have experienced some form of sexual harassment, as would at least 1 in 5 men. Human nature is less predictable and there are enough years for some form of sexual harassment to occur in those few years, particularly from people known to them, both men and women.
As an educator working on a large college campus, I have seen far more of this with my female students than I care to.
But the President's numbers come from the National Institute of Justice, whose study found that 19% of women reported a completed or attempted sexual assault since entering college. Not even just sexual harassment as you stated, but assault.
13.7% experienced a completed sexual assault, 4.7% experienced a physically forced rape, and 11% were assaulted while unable to give consent due to alcohol or drugs. These incidences are particularly nefarious, since so many people keep trying to claim these aren't "real" assaults- that the only "true" sexual assault is physically forced rape (which, by the way, is also 10 times higher in colleges than in the US population at large). The perpetrators of these assaults seem to think it's fine to drug a woman or push her to get drunk then take advantage of her when she is unconscious or barely conscious- the fact that they rarely receive more than a token punishment for these acts gives them that illusion.