to distinguish between portmanteau words, in which non-leximic elements are smooshed up into each other (e.g., smog, from smoke and fog) and words built up from legitimate lexemes (e.g., educrat).
Cool, Faldage! I hadn't really thought/known about this, but yep, if one is one thing it ought not be called the other.
So--if -crat is a lexeme, is -cracy also? What about demo-?