Yes, there is an idiomatic way of saying this in Japanese. One possible expression is 「類は友を呼ぶ」(Rui wa tomo o yobu), which can be translated as "Birds of a feather flock together" or "Like attracts like". This expression implies that people tend to associate with others who are similar to themselves in terms of personality, background, and interests. It can also suggest that people tend to maintain the status quo by surrounding themselves with those who share their values and beliefs. In the context of maintaining a hegemony, this expression can imply that those in power tend to associate with others who share their views and interests, thereby reinforcing their position of authority.