Back in 2000, I put forward a theory of why, 500 years after Cortez, Mexico, like many Latin American countries, is still run by largely white people despite no sharp color line:
... Now, in Mexico every century or so, there is a massive upheaval like the Revolution of 1910. The white monopoly is fractured. Up through the cracks come the most talented mestizos and Indians. They start dynasties that persist to this day … but their grandsons and great-grandsons are notably whiter than they were, since the men of the family have been exploiting their social ascendancy to marry white women. (Of course, many rich Mexican men father second families with their lower-ranking mistresses. But these kids seldom get the breaks in life that the legitimate children do.)
The late Venezuelan presidente Hugo Chavez, whose family life I wrote about in 2010, would be a good example of a poor man of pardo background (Indian, black, and white), who clawed his way up in life. But, I suspect his grandchildren, especially by the second wife he obtained after becoming successful, will be quite a bit fairer than him.