In the ongoing war to boost the federal minimum wage, the skirmishes have been getting larger and louder, yet success seems as far away as ever.
The latest round of protests Thursday targeted Wal-Mart, with organizers turning out crowds of varying sizes in 15 cities across the country demanding the world's largest retailer pay all employees at least $25,000 a year and stop what they claim is retaliation against strikers.
Two former Wal-Mart workers and one current employee were arrested in New York outside the Manhattan office of investment banker Christopher Williams, a member of the Wal-Mart board of directors.
Labor experts say that proponents of an increase in the $7.25 an hour federal minimum wage, which buys less in real terms today than in a half century, face a set of powerful economic winds that have been blowing for decades: the weakening of unions, the flattening of wages versus productivity, sluggish economic growth and tepid support from politicians.
Thursday's protests followed similar demonstrations last week when thousands of workers at fast-food restaurants in dozens of U.S. cities walked off the job demanding higher wages. Organizers called that effort one of the largest strikes ever against the nation's fast-food companies.
The debate over minimum wage has taken on new energy as the average worker's wage remains stalled in an economy still trying to shake off the lingering damage of the Great Recession. But the lowest paid of American workers have been steadily losing ground to a variety of economic and political forces since the 1970s.
The Fair Labor Standards Act of 1938 established the hourly minimum wage rate at 25 cents for covered workers. Since then, it has been raised 22 times, in part to keep up with rising prices. The latest boost, in July 2009, brought it to $7.25 an hour, or about $15,000 a year for a worker putting in 40 hours a week.
Opponents of a higher minimum wage, supported by a number of economic studies, contend that it would eliminate the very entry-level jobs that low-skilled workers need the most.
Wal-Mart officials say the recent protests don't reflect the views of all of its workers, and that its low-wage jobs offer entry-level employment for low-skilled workers who can earn more as they develop skills and take on more responsibility.
More than 99 percent of Wal-Mart employees make more than minimum wage, and some three-quarters of the company's U.S. managers began with the company as hourly workers, Wal-Mart CEO Michael Duke told CNBC.
"Whatever we do, we sure don't want to take away from the opportunity to get started and the opportunity to grow and be a part of personal growth as well as the growth of our business and the growth of America," he said.
Wal-Mart has also responded forcefully to the periodic protests by unions and other labor groups calling for the company to boost pay and benefits.
In June the company filed a lawsuit in Fort Worth, Texas, against the United Food and Commercial Workers International Union for what it claimed were "confrontational and abusive" demonstrations at stores around the country over the past year.
"They have screamed through bullhorns, paraded around with banners and signs on sticks, conducted in-store 'flash mobs,' and diverted management and local police from their normal job functions," the lawsuit said, according to NBCDFW.com.
The company has filed similar legal actions against local groups in Florida and California.
Despite political support for increasing the federal standard, only 20 states and a number of cities have passed laws requiring higher minimum wages. (San Francisco, at $10.55 an hour, is the highest.)
(Read more: Fast-food strike gets supersized over wages)