Since minimum wage is not liveable, many minimum wage jobs are taken by teenagers, rather than heads of households.
Anyone who works with teenagers knows that having a job increases their self-esteem, especially those who don't excell in academics, sports, or other school-based activities. At work, they feel needed, valued - yes, even at minimum wage, they are valued - and held to high standards that they are able to meet.
They learn the value of work on a team, and the importance of "making a hundred" in every task, not settling for 70%. They are thus more likely to become successful adults after learning a skilled trade. Or they realize that more education means more money, and they begin to excell academically, and become engineers, accountants, or other jobs in which the title of the major is the title of the occupation.
Such teenagers are not likely to grow up and vote Democrat, which is another reason Democrats oppose entry-level jobs.