How do you know what OUR tradition is? MY religious background would deny you any alcohol, any day of the week. Since when is a tradition a good basis for a law? Yarmulkes have a long tradition behind them in Judeo-Christian tradition; shall we pass a law that requires them being worn? How about mandatory facial hair for men?
No one is forcing you to forgo your traditions; you can easily NOT make Sunday purchases of booze. If the tradition is so strongly held, I am sure booze sellers will quickly find it unprofitable to pay employees, and stop selling it. Or, maybe the real tradition here is hypocrisy, because both you and I know that blue laws aren't stopping the booze drinking on the Sabbath.
I'm not talking about your family's tradition. I'm talking about the community tradition which in many places in the South (as well as other parts of the US) involved the prohibition of the sale of certain kinds of things on Sundays.