If you'd like a more concrete example, how about we look at the effects that these minority/majority impacts have had on the delegates sent to the presidential college?
Here:
https://en.wikipedia.org/wiki/List_of_United_States_presiden...
As you can see you have several states that have always voted for the same party for decades.
For example, Alaska, Idaho, Kansas, Nebraska, North Dakota, Oklahoma, south Dakota, Utah and Wyoming... Have voted for the republican candidate every single year since 1964. How many Democrats live in those states? These are literally millions of people who by virtue of being a minority have had exactly zero agency in who will rule over them.
On a more local level, how many regulations are voted on by people in cities, but will inevitably affect rural people? Or heck, any people who did not want those regulations?
For people being oppressed, who have no actual way to prevent their oppression, does it really matter if the oppression is being done by a dictator or a vote?