The constitution should begin with a prelude stating that any words to follow are entirely random, strung together through the use of a random number generator, and any references to any persons alive or dead, events, or places are entirely coincidental in nature. And then follow up by telling Zizou and co to kindly appreciate satire and hyperbole. From there, but this is just what I would do, you could insert words that make no sense as you see fit, and produce an odd laugh or two.
Alternatively you could open by saying that the following has been approved by an oligarchian power structure who wish at all costs to avoid disenfranchisement by giving you no rights to begin with. This is a great segway to humorous descriptions of the drafters of the constitution, those who you should all credit for their intellectual contributions. Make sure to tell everyone to abide to the constitution by the letter, never alter its contents in the slightest for fear of treading on the philosophical feet of the founders, and that all flaws present in their character and actions can be safely ignored in the name of patriotism. It will be just like America.
For substance itself, you could go on to a rule bashing unceremonious use of 'no u', 'I call bs', 'o rly', 'no rly', and all derivatives. Basically think of some things you don't like, and address them as rules so that you will have a subtle influence on the actions of anyone impressionable enough that they always act to appease. Oh, how about a rule stating: "While nothing of note is going on in chat, feeble attempts to instigate some sort of conversation must be made regardless of the quality of the ensuing discussion or its participants". Or a rule saying: "Pretending to ignore someone while making a point to tell them they are being ignored is punishable by use of the acid machine". Another idea I've got is: "Making ideas, people, events, and facts up, or openly contradicting yourself, then consequently laughing when nobody notices is rewarded with a free story to tell about how great you are". I've got more ideas, I do.
But for now I'll just post this. Afterwards, I'll attempt to upload my 2 fake chats, and hope this computer can do it.