In the United States, representation is a function of geography, not ethnicity. Ethnic representation is, within the United States, unconstitutional.

Other nations may have different rules. France, for example, is proposing the creation of "expatriate" seats in their Parliament, to allow expatriate communities of French citizens representative voice in French government.

Personally, I consider ethnic representation to be unwise for national government. Even when ethnicity lends itself to distinct cultural characteristics, and when the ethnicity in question sustains a distinct society of its own, I cannot see any ethnicity interacting with a larger government in single lockstep as a monolithic entity/society within the national society. People interact with the larger society, the larger government, as individuals, and it is individual people that therefore should be represented. Ethnic representation is not representation of the individual.