I'm all in favor of a bare minimum hourly wage. But it should be a livable wage. However, I don't think you can apply the same wage all over.
By that I mean, a national $20 or $25 an hour wage. My view is that it should depend on the state or county.
$20 an hour works in LA maybe, but in small town Mississippi it would kill the local economy because the cost of living for both are vastly different.
It is why I think a national minimum wage won't help. I think there should be some sort of formula for each county based in part for the cost of a 1 bedroom apartment for a family of 3 or 4 maybe. Or whatever metric. It could be $14 an hour in a town of 2000 people in Mississippi or $20 an hour in Orlando but that may not be enough for very high standard of living cities like San Francisco or NYC and so it could be $30 an hour there.