IMO the best model is to have a dictatorship transition into a functional democracy, by providing initial stability, which later carries over into long term stability through free elections. Thats how it happened in almost every example of a functional democracy there is today.
Except Britain, France, Ireland, the United States, Belgium, the Netherlands, Sweden, Norway, Denmark, Finland, Canada, Australia, New Zealand, Austria, Switzerland...
But, uh, you've got South Korea. That's a good start.
Or it would be, if the South Korea dictatorship had actually been stable, if it hadn't been three successive dictatorships, each of which ousted the other.
Um.
We have seen, here in the US anyway, that class-reductionism led to a racist left that alienated and excluded people of color, while race-reductionism led to reactionary nationalist and religious separatist movements. The actual originator of the phrase "identity politics" took all the important socialist positions mentioned in the text you quoted there. This is why you need intersectionality. Intersectionality is the opposite of fundamentalism or reductionism of whatever kind.
Okay, but: when?
The last significant left-wing formation in the United States that you can plausibly argue emphasised class to the exclusion of race was the Socialist Party in the early twentieth century. All the movements that followed them- the IWW, the Communist Party, the New Left- were all explicitly and emphatically anti-racist. The parts of the left that weren't willing to talk about race were absorbed into the New Deal coalition and shortly afterwards stopped talking about class, either, which they'd never much enjoyed talking about the place in the first place.
The thing is, you do see exactly this phenomenon in Europe, of leftists who are happy to hammer on about class, but are uncomfortable talking about race. What you don't see is the development of American-style "identity politics" as a response. So somewhere along the line, the narrative has got pretty scrambled.