To me it is not whether such a law would be justified, but whom it would hurt and whom it would hurt.

Anything that makes hiring the bottom end of the labor pool more expensive will decrease the amount of that pool that is hired. There are some who claim studies that show this is not true. I claim these studies are dopey. If it were not true that raising minimum wage causes fewer from the bottom to tbe hired, why not raise it to $20/hr? $50/hr? Can anybody who even bothers to fully oxygenate their blood fail to see that if you raised the minimum wage to $50/hour there would be massive unemployment? Well tickling the wage down around only $7, $8, or $9/hr is the same thing, only writ small enough so that what is blisteringly obvious with bigger numbers can be missed by people who want to pretend it isn't there.

If the minimum wage is raised, it will LOOK successful in the sense that the people who still have jobs, who still get jobs, will be paid more. Guess who will lose jobs? The hardest to hire. The least capable.

So if you feel more comfortable pretending that everybody can work and make a certain amount of money, AND it is easier for you to ignore the people that can't get jobs than to pretend that $7/hour is enough, then keep going down this road. Put the hardest to hire out of the labor force entirely, pay for them on welfare, and pretend they don't exist while congratulating those that still do have jobs on what a good job you did for them.