Workers who make the minimum wage live from pay check to pay check, that is why they are refereed to as the 'working poor.' They have no expendable income and the United States government must subsidize their income with social benefit programs because they do not have enough money to support a first world standard of living. Raising the minimum wage does not give these people more money to work with, it just takes them off the government dime.

Instead of paying groceries from food stamps they will make the purchase out of their own wages. Instead of wasting food stamps on frivolous luxuries, they are paying for luxuries out of their own pocket and still have enough money to pay their own way. This is especially important if you are a conservative who wants to impose harsh trade regulations and tariffs on foreign imports to bring manufacturing jobs back to the United States because the cost of labor is significantly more expensive and these worker-driven manufacturing plants will have to compete with highly productive, automated manufacturing plants. For evidence, just look at US manufacturing productivity. It has risen steadily over the last several decades even as the number of people employed in the manufacturing industry has declined.

To summarize, a living minimum wage of ~$15 an hour acts as an economic stimulus by increasing the spending power of the consumer. It reduces government spending on social welfare programs by raising people above the poverty line. Finally, it is necessary for citizens to have more expendable income if local manufacturers are to be competitive with foreign imports.