Darlene Handy of Baltimore holds up a banner at a rally supporting a pay measure in Maryland. More than 20 states have raised minimum pay rates above the federal level. Jose Luis Magana/AP hide caption

itoggle caption Jose Luis Magana/AP

A Denny's waitress delivers breakfast to customers in Emeryville, Calif. The tipped minimum wage has been stuck at $2.13 since 1991. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

President Obama, working at his desk Monday night on the eve of his 2014 State of the Union address. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP

Protesters rally outside of a Wendy's in Brooklyn, New York, on Dec. 5 in support of raising fast food wages from $7.25 to $15 per hour. Andrew Burton/Getty Images hide caption

itoggle caption Andrew Burton/Getty Images

Fast-food workers march toward the Smithsonian's National Air and Space Museum in Washington, D.C., on Thursday. Similar rallies occurred in about 100 cities across the U.S. Morgan Walker/NPR hide caption

itoggle caption Morgan Walker/NPR

Voters in SeaTac, Wash., have narrowly approved a measure raising the minimum wage at its international airport, officials say. But the initiative faces several challenges, including a recount. Elaine Thompson/AP hide caption

itoggle caption Elaine Thompson/AP

New York City Council speaker and then-mayoral candidate Christine Quinn speaks at a fast-food workers' protest outside a McDonald's in New York in August. A nationwide movement is calling for raising the minimum hourly wage for fast-food workers to $15. Richard Drew/AP hide caption

itoggle caption Richard Drew/AP

McDonald's USA President Jeff Stratton responds to an employee who burst into an event. YouTube screengrab hide caption

itoggle caption YouTube screengrab

Outside a Taco Bell restaurant in Warren, Mich., early Thursday, supporters of the push by fast-food workers to raise the minimum wage were marching. Jessica J. Trevino /MCT/Landov hide caption

itoggle caption Jessica J. Trevino /MCT/Landov

People gathered outside a Wendy's restaurant in New York City on Monday as part of a one-day strike calling for higher wages for fast-food workers. Justin Lane/EPA/Landov hide caption

itoggle caption Justin Lane/EPA/Landov