When Martin Luther King Jr. took part in the 1963 March on Washington for Jobs and Freedom a central demand was a $2/hr minimum wage. In 2014 that is approximately $15!When asked for any evidence to support that claim, we were given four links (for instance, this one). Which were all claims from 2012 and 2013 that a (near doubling) minimum wage increase was an issue in Martin Luther King Jr's March on Washington back then. However, the man whose birthday we're supposedly honoring next Monday, didn't bother mention it in either his I Have a Dream speech, nor in his famous Letter from the Birmingham Jail.
Both of those are all about freedom, not coercion.
Possibly King didn't come out for a higher minimum wage because he knew that historically they had been used to prevent negroes from competing for jobs held by whites. The people who passed the Depression era Davis-Bacon Act made no secret of their racist intent; to keep construction jobs on public works reserved for white dominated trade union members.
The chief victim of today's $9+ minimum wage in the state of Washington are black teen-agers. They're the ones who have been priced out of entry level jobs. Kshama Sawant and friends are co-opting Martin Luther King for a racist law.