Interns are always underpaid, if at all. THey benefit from the experience.
Of course, Dems never apply that reasoning to what should be a workforce entry-level job—burger flipping. That’s because the constituency affected by this is largely not of entry-level age, and will never be qualified for a more sophisticated job.
In the long run, raising minimum wage (and raising the welfare floor) will create increased automation and also wage-push inflation. After all, if a burger-flipper is worth $15, what’s a union member worth?