you know what...i asked myself the same question and looked it up ages ago. i am not american (well..not really anyway)i only vaguely remember...oh we are such geeks :)
but i think a chad is something that you get when you punch a hole or any symbol into a piece of paper. and so the hanging chad is one that is still attached to the paper..this is really hard to explain..
let me look it up again..there was some election scandal..because its unclear if the paper with the hanging chad was bra half empty or bra half full if you know what i mean :P

link)

Your first post makes sense but the second link doesn't go to anything. It says Page not found

i dont know why the closing bracket is not included in the link..you might have to add that manually and it should work..

I don't know if this helps but link