If there is a single imperative that is driving the leftist agenda - a P1 principle component so to speak - it is the determination of women to shatter all constraints on their continued sexual profligacy. The women in our society will sacrifice absolutely everything to ensure it. Anything that discourages them from sleeping with whomever they like, whenever they like, utterly without consequences either physical or moral, must be destroyed. They will happily see whole cities reduced to dust and the earth salted afterward, than submit to even the most mild constraints on their sexuality. Reason itself will be turned on it's head if necessary, in the interest of achieving that goal.
The risk of pregnancy has always been foremost among the various concerns regarding female promiscuity. Therefore, according to women, society must be twisted and turned however is necessary in order to eliminate it. That's really all the abortion debate is. It's a debate on making sure women can sleep around as much as they want, for as long as they want. That's it.
Now obviously there are a number of men who will support increased female promiscuity as well - and for obvious reasons. But when women are allowed to sleep with whomever they like, they all end up choosing the same few highly attractive men. Those few men go through a great many women than they otherwise would, and the men who are somewhat less desirable to women, often end up with no one at all. So for all their support of Feminism and the female sexual prerogative, they are really only participating in the destruction of a system which was probably already best for them in the first place. And in the end, it's this female promiscuity initiative and it's long term effects on our culture, and our demographics, which will inevitably destroy the west.
Women are not the same as men. They never will be. And so long as we treat them like they are, the end will be approaching much faster than we think. You cannot speak reason to them about this - they will not have it. So unless we find a way to control them and in the process restore some semblance of monogamy as the most acceptable standard for relationships, all will eventually be lost.