You are correct-it is the basis for our entire culture and society. Now, down to business:
Traditional marriage has 3 elements:
1) It is permanent (no divorce)
2) It is sexually exclusive (adultery is a felony)
3) It is between a man and at least one woman.
Which of these does your amendment restore?
You've included that as an element of traditional marriage a couple of times. I don't understand the "at least" part. Perhaps you're playing loose with ther term "traditional marriage" to include what's practiced in some cultures not influenced by Christianity?