The difference between ‘elite’ and ‘elitist’ is the same as the difference between ‘Islamic’ and ‘Islamist’. I’ve not checked any etymological resources, but I’m betting ‘eletIST’ was probably coined as an analog to ‘racIST’. It certainly is used in that way today.

It’s an apropos usage, in my mind. A person may be undeniably white and elite (at something), and simultaneously neither racist nor elitist (I give you William F. Buckley as exhibit A).

I think the reason the word has this connotation is because it DOESN’T modify any noun. ‘Elite’ is an adjective that should tell us what the person is especially good at — an ‘elite athlete’, or an ‘elite author’, for example. Having no noun to modify implies that a person isn’t just better at SOMETHING than others, but that he is — or thinks he is — simply BETTER, in very much the way a racist white person assumes himself better than a black person. Some people are certainly superior THINKERS, or SPEAKERS, or POLITICIANS — or plumbers or accountants or computer programmers for that matter — but is anyone simply ‘superior’? Better intelligence, better compassion, better judgment, better morality — just ‘better’? More ‘evolved’, perhaps? This is, I think, what people mean when they refer to an ‘elitist’ or an ‘elitist attitude’. It implies a sense of self-superiority that carries with it an entitlement to power over the masses.

We need a word for that, and I think ‘elitist’ works very well.