this is doable and wouldn't have to cause layoffs if he limited CEO pay like in Denmark. Say that no employee can be paid any more than say 7 times more than the lowest paid employee in the company. So if the janitor's making around $15k a year ($7 an hour with a 40 hour work week before witholding tax), the top CEO can't get anymore than $105k a year. And how can $105k a year not be enough?
105K a year is very little money in much of the US. And certainly either $5.15 an hour or $7 an hour is truly desperation level income. But minimum wage laws are authoritarian interventions in private interactions. If we were more honest with ourselves we'd recognize that the working class is inevitably going to lead a poor sort of life, and no amount of restricting of freedom can change that.