Fantasy politics: Law and government in a world with multiple sentient species

[So rightwing that I broke the Political Compass!]

I was initially going to make this a thread about law in a world with "magic", but magic is too open ended(and frankly anarchic). So nothing outright magical(wizards, or trolls that turn to stone, or what have you). Dwarves and (reasonably sized) giants are ok, werewolves and talking dragons are not. I'm counting on you to self regulate in this regard.

First and most obvious topic for discussion: Constitutional treatment. Assume that your representing x constituency at a constitutional convention, and that enlightenment principles not too different from our own are the norm in this world.

For the sake of discussion assume theirs a fairly wide variation among the specieis in terms of average intellectual capacities, instincts, etc. But none are stereotypically "good" or "evil", and all are functionally individual rather then ant-like hive minds.

[FEMA Camp Administrator]

The white man, by crossing the Rocky Mountains, has driven the trolls from their native land. We'd like vast expanses of mountain to be guaranteed to go untouched, plus all the casino stuff.

(But then again, some claim the trolls already have their own state:
)