Mexicans have been doing that since as long as I have lived, it is how they take over occupations in America, so completely.
Yes, Latinos are prime examples.
One medical residency hospital had almost all slots filled by MDs of India ethnicity and they were broken up because of it. The residency program was actually shutdown as it had its funding pulled (Medicare funds residency programs).
Every year there is a residency ‘Match’ program for new med school graduates and it is super competitive. Whenever a new med school grad gets accepted at a residency, he or she go there without question even if it is in a ghetto. No complaints are made, no pleas for other matches etc. A new MD is just happy to get a slot.
People of different ethnic groups like from India get into residency programs and then become head residents or become MDs that work in the residency program supervising the new MDs. This is when the clustering starts.
Such clusters can be broken up,
If a heterosexual person were able to get hired by the NY Times and they had the courage to file a lawsuit against the NY Times for their homosexual clustering, they could possibly break it up and change the culture there.