The answer is "wanting to disguise the truth they have uncovered."
Some historians find this tough. One of the reasons would be because not all people may or may not, like the truth. Some historians would omit some part of the truth to keep violent reactions from the readers or outsiders.
Is this an opinion I say Idaho but if not I say New Mexico
They are examples of discrimination.
In apportionment system, representation is distributed among the constituencies of a representative assembly.
This term only commonly used in American term. It is usually arranged to ensure that distribution of legislative seats reflected the will of electorate.