For decades the ABA (through various groups) has sponsored various uniform model laws. (the most famouse around here would be the Uniform Commercial Code) This has been part of a long envisioned movement to "harmonize" all state laws.
Of course there are limitations such as states that have income taxes vs those with no state income tax.
However the movement is fairly successful, the present divocrce model code completed for some time, even has provisions for homosexual marriage with children as mere accessories.
The reason I mention all this is because I see states rights started to be slowly and inexorably pushed aside. The marriage situation is an excellent example, the homo-activists and leftist commies are now able to use full faith and credit to effectivly undo or impose any social whim they have through the courts bypassing any individual state rights.
I don't see anything wrong, in principle, in having basic 'model' laws that apply to most people in most states/localities. A good 'for instance' is our right to concealed carry. -- It should apply nation wide.
That's why we need a constitutional amendment.