voting your enlightened self-interest

What could ‘enlightened self-interest’ possibly mean? Isn't enlightenment supposed to be incommensurate with self-inolvement?

I suppose that depends on what you mean by ‘self’ and therefore by self-interest.

If by ‘self’ you mean your body and the collection of possessions under your control, then the phrase ‘enlightened self-interest’ must seem like so much nonsense, in which the word ‘enlightened’ will have been reduced to another way of saying self-interested, rendering the phrase redundant. (This view, if expansive enough to include a concern for reputation, is likely to lead to relative material prosperity, that is being more prosperous than others.)

On the other hand, if by ‘self’ you (also) mean your mind and its sociocultural environment, then your ‘self-interest’ may extend to conditions which don't directly or only marginally impinge on your own life. (This view, if sufficiently grounded in reality, is likely to lead to social stability and long term sustainability, with distributed, moderate material prosperity.)

So think a moment before you cast your vote, whether you are giving your support to the ticket which better represents your enlightened self-interest, or to the ticket which would be better described as waving it in your face, as a matador waves his cape at the bull, concealing a sword behind it.