Raising the federal minimum wage is gaining momentum as state and local governments increase their rates and Democrats look to push the issue as a winning campaign pledge ahead of the 2014 elections.

Minimum wage increases got a boost this year from successful measures around the country. California, the most populous state, led the way by legislating a rate hike to $9 by 2015 and $10 by 2016. There were also hikes in New Jersey and New York, as well as in places like the Seattle-Tacoma International Airport, which raised its wage to $15. And labor unions have been pushing fast-food workers around the country to agitate for a $15 “living wage.”