Important but finite.

EDIT Adding on -- analogy off the top of my head: the USA is like a mom and dad and fifty unruly teenagers at home, with an "our house, our rules" system. The teenagers can do whatever they want: California can dye its hair blue, Florida can do Florida things, but just don't break the overarching rules the house requires/prefers to run on. In return, there are some serious benefits to living under this particular roof.

Important but finite.