As far as I can tell, I don't believe those who promote a living Constitution believe it is a "free-for-all" to interpret however we want. To draw a little scriptural analogy, which many on the right are so fond of anyway in spite of the First Amendment and the "no religious test" of Article VI, why can't we "liken the Constitution unto us" and consider its principles as applied to our current situation?
The debate on this is not new. I can't solve arguments that have been going on since the Founding. I could, if I wanted, proof-text the Founders even if I prefer proof-texting the Prophet Joseph Smith. But my point is much easier than all that. This is the People's Constitution. It says so in the very first three words. We the People are the ultimate power and We the People decide how to interpret and use it. That's even consistent with the Tenth Amendment (in spite of the fights about the missing word "expressly") as it acknowledges that the People are the source of and retain all power not delegated to a national government or the states. By the way, that's also the argument of Brother Joseph above. He just believed it to be exercised by the People through Congress. (Eew!) Yet it's more than just the Congress. We also have a say in Presidential elections that in turn result in the appointment of Supreme Court Justices. We vote for the Senators who confirm them. We can petition our government and we can participate in the public fora (including this modest little blog) that cumulatively add to the public view and will of our own self-governance. And, most importantly, we can each practice civic and moral virtues that tend to promote "a just and lasting peace among ourselves and with all nations."
The clincher to all this and what causes so many conservatives heartburn as evidenced by the ongoing immigration debate is the Fourteenth Amendment. That Amendment, constitutionally enacted even at the cost of much blood - I admit we never would have had it without a Civil War to preserve our Constitutional Union and free an oppressed group of human beings - should be read for what it is - a grant of power to the United States government of, by, and for the People to protect a heck of a lot of rights not specifically enumerated. Read it some time.
In fact, I'll help you out. Here's the first and last sections:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
The Congress shall have power to enforce, by appropriate legislation, the provisions of this article.The Fourteenth Amendment has been argued about since its enactment - as it should be. And this is exactly my point that is the structural process and protected freedoms of our democratic republic that make our Constitution live.
Read it. Participate in our process. We the People are not going away. And I'll be doing everything in my power to make sure our Constitution continues to live as well.