To be frank, women's sufferage really was formulized in 1848 arguably, and then took until 1920 to actually happen. During that time, there was similar discussion to what we're having now. The idea of basic values have changed because of cultural discussion, over the course of decades.
I would argue that equality of sexualities has increasingly become another core value, with the debate of such happening over similar amounts of time. The discussion of course is still ongoing in this field and I'm eager to see what will happen in the future.
One of the points he makes is that the left and right don't agree on what the words "equality" or "fairness" mean. Right wing people tend to focus on equality of process. Left wing people tend to focus on equality of outcome.
That is, a conservative will tend to say "is the hiring process fair? yes? then if 90% of the jobs go to men, there's no problem". Whereas on the political left, they may say "if 90% of the jobs go to men then by definition the hiring process is not fair, and we should find a Solution, like by setting quotas". Right-wingers will tend to reject direct intervention like that, as they don't trust in human ability to intervene without causing unexpected and undesirable side effects.