For liberals to state that all people are born equal and that this is a condition that can neither be gained or lost, is to describe a static - even tranquil - condition.
By contrast, the same liberals' idea of Progress sees all humanity as being born 'involuntary participants' in a series of life-or-death gladiator competitions ; Progress merely being Social Darwinism in its political correct dress-coat.
Life or death competitions where even the 'happy' winners are always looking back over their shoulders and where the losers believe they will lose their lives, in the long term if not in the short term.
So in the 1930s let's say, it was currently felt that the White race was winning over the Yellow race but that could change, if the Whites ever let down their guard for even a minute.
And within the White race of the 1930s, the Anglo Saxons were winning but the Jews were gaining, and so the Anglo Saxons must ever keep up their guard and even consider new counter measures.
While within the Jews, physically and mentally defectives were losing the intellectual race but winning the demographic race.
The idea of Progress is what allowed - is what allows - liberals to have their cake and eat it too : talk of equality but encourage a tigers' den of winners and losers.
But 'riding the tiger of progress' was uneasy work - and hence the Era of Modernity was noteworthy for its frequent communal pogroms of violence, fear and hatred against other 'gladiators' --WWII being merely the worst and best known....