The minimum wage isn't earned only by people working at fast food restaurants and in service industry work - the average income for positions like nursing assistants, preschool teachers and paramedics are all under $15.

A September 2015 poll found that, by a 3-1 margin, voters are more likely to support political candidates who favor raising the minimum wage.

Most fast-food workers can't easily join a union, because they don't work directly for their parent company, such as McDonald's or Subway. Instead, they work for individual franchise owners, ensuring that each individual fast-food outlet would have to organize and win union recognition separately. So there's not one central employer to bargain with, as in a traditional union campaign.

People decide what markets should do - they are not a force of nature.

Income inequality and wage stagnation finally took their place among the principal moral issues of our time.

The vast majority (over 80 percent) of fast-food and similar low wage service jobs (<$9.24/hr) are held by adults. A quarter are adults over 40. Another quarter are moms raising kids.

Fast food also has a uniquely difficult business structure for workers to achieve better wages and working conditions.