the cry of "Diversity!" is invoked exclusively by those who are trying to import to a group those demographics which tend to offer political support to the left.

I wouldn't mind "importing a demographics which tends to support X" assuming that we continue using the existing filters on content, and require rational comments and avoiding mindkilling politics. The difference between 55% and 44% seems unimportant, because we don't use majority voting in LW anyway. It's not like a 5% advantage would make someone win or lose an election. Unless we really lose our basic community values, it wouldn't even mean that the minority group would automatically get negative karma for every comment.

I am more concerned about "importing a subset of a demographics, selected by its support for X". As a strawman example, by suggesting that we need more Obama-voting women, but we actually don't care about Romney-voting women. As a more realistic example, by trying to optimize LW for women from the feminist / social justice warrior cluster, instead of for women in general. (Because, you know, there are also women who prefer free speech, and some changes would make LW even less attractive for them.)

Therefore I think new demographics should be invited here, but in a way that does not signal preference for a political group X. Specifically, we should invite women, not feminists. (If some of those women who come happen to be feminists, that's perfectly okay. As long as they are equally invited if they are libertarian, conservative, neoreactionary, or whatever.) If we want to invite the demographics, let's really invite a demographics, instead of making a power grab for a political group X in the name of inviting the demographics.