Slavery is alive and well in the U.S.
Slavery can only be imposed with the use of force. Since it is only the government which can use force to achieve its goals (in the US anyway), then only the government can institute slavery. Since a minimum wage (or any wage controls at all) can be viewed as fixing the value of someone's labor in spite of it's value in the market, then this could be viewed as a form of slavery.
Another spin on this might be that if the government forces one person's labor to be valued at a lower value simply to lend preference to another individual (or group) then this might be viewed as slavery as well.
So by not eliminating that minimum wage law, the government could be viewed as promoting a brand of slavery, but personally I think it's a harsh assessment.
I'm sure this is what you meant right? What does this have to do with the people who work at wal-mart of their own free will?
Cashiers in our area start between $6-7 per hour. I should know, my wife works for our local Wal-Mart in the accounting office.
It's worked well for us because she works nights on weekends so we haven't had to put the youngest in child care. She's leaving there to go back to teaching part-time this fall.
But from our experience, Wal-Mart has been an excellent company to work for.
Don't seem to remember the "mom-and-pops" paying any better. In fact most of them paid even worse if you consider the total lack of benefits. I remember working at a "mom-and-pop" for $2.00 a hour under the table (they wouldn't put me on their official payroll). The minimum wage at the time was $2.65.