Is essentialism needed in democracy?
Of course, it is. Not only it is, but it is vital.
Through the democratic conception of the individuals and the interactions between individuals, essentialising is one of the most effective way of protecting democracy from any constructive criticism.
Democracy has it that people are the same all over the world except for some differences. While this might sound weird, still it is the one of the democratic hard core beliefs. Everywhere the same needs, the same dreams, the same wishes etc..., a thought that leads democratic people to design those famous democratic values and rights everyone on earth is entitled to.
Now this explains their leaning to find and put in front the differences that might appear to explain any distortion between the expected result of democracy and the real result.
If they cant assess to liberty, it is because they are black. If they cant have the possibility of vote, it is because they are women. If they are acting this way, it is because they are this nationality or that nationality etc... The examples are so numerous since the birth of democracy and such a common use today that being exhaustive is impossible.
Again, democratic people recognize that the identity of a person is a composite of many things. Yet each time, democracy leads them to blame the differences to explain a malfunction.
Indeed another approach would be to consider that if there is something to essentialise, it might be not what people have different but what they have in common.
Of course, such a way of thinking leads to put into light democracy which is the only common trait each time essentialism appears, an alternative which is naturally excluded.