By Josh Harkinson, May 21, 2015, Mother Jones

On Tuesday, Los Angeles became the third major West Coast city to pass a $15 minimum wage ordinance. Though the law won't fully go into effect until 2020, it's a huge deal. LA is larger than San Francisco and Seattle, the two other $15-an-hour cities, combined. It also has a much larger contingent of low-wage workers. The ordinance will give a raise to an estimated 750,000 Angelenos, or about 46 percent of the city's workforce.

LA's wage hike points to the potential for a major minimum wage boost to sweep the country. Although experts disagree about the LA measure's impact on growth and employment, the City Council passed it by a 14-to-1 margin. The $15 wage polls well in LA and nationally, despite a dearth of national politicians pushing for such a large increase. If organizers play their cards right, this suggests a $15 wage could gain traction in other cities.

So how did it happen? The original proposal, after all, was a more modest one. The measure's backers attribute their success to a combination of grassroots and national organizing. The umbrella group leading the push, the Raise the Wage Coalition, includes more than 260 local organizations from labor, business, entertainment, and the civil rights movement.