I agree with you, but let's face it, it is the backbone on which our law exist. Other than the 10 commandments, the DOI Is the single document which everything this country stands for is derived from and the minute we are willing to let others trample it, that's the day we are no longer free.
I've always been curious about the allegation that the 10 commandments were somehow related to the creation of our legal system. I've never seen an American law that enforces commandments 1 or 2. (No strange gods and name in vain.) With the dissolution most blue laws, you'll be pretty hard pressed to find laws dedicated to keeping the sabbath holy (or free of football, for that matter. I think most of the prayer that god gets originates during the playoffs).
Commandment 4 (honor father and mother), 6 (no adultery), and 9 - 10 (covetousness of wife and goods) are likewise also not framed as laws.
Sooo...because there are laws against murder (C5), theft (C6), and perjury (C8), the 10 commandments are a source of American jurisprudence?
Hey, 3 outta 10 IS 30%. That's almost enough to get you elected...in FRANCE!