I agree that a lot of hot air is produced, in any language. However, the example from the OP seems to me quite clear in its meaning, on two premises: a) only voters of either Republicans or Democrats are being considered, and b) a sufficiently precise definition of "middle class" is agreed on.

"The middle class is even more evenly divided" would be even clearer.

Polls with questions like "Do the rich deserve their wealth?" are much more questionable. All statistics have in common that they may be faked - a problem of neither language nor logic.