Endogamy vs. Exogamy

[Geremia]

Summa Theologiæ II-II q. 154 a. 9 co.:

it is natural that a man should have a liking for a woman of his kindred

cf. St. Thomas on Aristotle, 2 Polit. iii., pp. 92-95 of this transl.

Interracial marriage is not common sense. It's not a sin, it's not an offence against God, necessarily, but it may often be an offence against common sense. Because there is too much difference between people of different races for their marriage to probably last. You're going to say that many interracial marriages do last. Fine. Undoubtedly. But it is still not a good idea [...] it's pretty deep, the differences between the races are pretty serious. Blacks should normally marry blacks, whites should normally marry whites. Chinese should normally marry Chinese [...] If you're in upper class in society you should marry upper class, if you're lower class you should marry lower class. It's common sense.

source: this Telegram post. Does anyone have the original source of this? It it from a sermon?