How Does $15/Hour Minimum Wage Help the Unemployed?

Robert Reich makes a case in this video for $15/hour minimum wage legislation.   

Reich, a current government employee and former government bureaucrat focuses on current low-paid employees and employers.  The major problem with framing the argument this way is that he totally omits the people most in need of income, the unemployed.

Question for Professor Reich:

How are the people unable to procure a job in today's $7.25 minimum wage environment going to find work at the much higher $15 level?

While we wait for a response, Thomas Sowell provides an alternative take on the real-life effects of minimum wage legislation...