This is my version of the Pledge of Allegiance.
"I pledge allegiance to the Constitution of the United States of America, and to the Republic for which it was written, one nation, under the laws of said document, indivisible, where liberty and justice should be for all."
After all, the flag is just a symbol of the nation. It's the constitution that makes the nation what it is (or should be). I mean, even when you join the military you are vowing to defend the Constitution, not the flag. If you pladge allegiance to anything in this country I believe this one is more fitting.