These campaigns also provide a glimpse of what is either labor's future strategy, or its back-to-the-future strategy, at a time when unions are increasingly marginalized.
"In the longer run, it is labor putting its chips down on the idea that it needs to heighten social consciousness and put social justice on the agenda in a major way," said Janet Fine, a Rutgers professor.
Unions are strengthening their relationships with community groups, advocacy associations, and congregations - that's what is happening with Wilmington's fast-food workers, the Jersey advocates, and the city's airport skycaps.
"People have been trying to count out organized labor for 100 years, so I don't believe in last hurrahs," Fine said.
"If labor is going to grow again, it has to alter the terms of debate," she said, beyond the traditional collective-bargaining relationship between employer and union member.
Unions have always grown most when they've been part of a larger social movement, she said.
Whether this strategy will be enough to renew organized labor's broader relevance to workers, or whether it's a last-gasp effort to stay afloat remains unknown.
At a rally outside a Wilmington Burger King where about eight cooks and servers walked off the job for last week's one-day strike, speakers included a Methodist pastor who heads the Delaware Ecumenical Council on Children and Families.
"We're tired of getting poverty wages," said another speaker, Darlene Battle, president of the Delaware Alliance for Community Advancement, as sweat beaded on her face.
With a raise, "We won't have to run out of here and beg for shoes for our children, or backpacks so they can go to school," she said. "We won't have to go to the thrift store to buy secondhand clothes."
In Washington, President Obama wants to boost the federal minimum wage to $9 an hour, up from $7.25, the minimum wage also paid in Pennsylvania, New Jersey, and Delaware.
Pennsylvania State Sen. Christine Tartaglione (D., Phila.) is shepherding a bill to raise the state's minimum wage to $9 an hour. Polls show that New Jersey voters, set to vote on a ballot question Nov. 5, favor raising the state's minimum wage to $8.25, with annual automatic adjustments based on the Consumer Price Index.
Proponents and opponents of a higher minimum wage both raise economic arguments.
Proponents say low-wage workers with more spending power will spend more, generating immediate economic impact. They may also have less need to rely on government help for food stamps or medical assistance to supplement their income - a hidden cost of low wages.
And, they argue, it's simply the right thing to do, particularly when companies are reporting significant profits and chief executives can command multimillion-dollar compensation packages.
A full-time minimum-wage job generates $15,080 a year, about $4,000 less than the federal poverty line for a family of three.
Opponents say most minimum-wage jobs are held by teenagers, who aren't relying on their wages to support themselves.
Employers, they say, will cut hires and hours if forced to pay more.
"It's one dollar an hour more, but it's $2,000 a year," said Philip Kirschner, president of the New Jersey Business and Industry Association. "Two thousand dollars a year per employee isn't something small businesses can absorb."
In New Jersey, a labor union leader, Charles Hall, also heads a 400-group coalition, Working Families United for New Jersey, the organization heading the statewide campaign to pass the minimum-wage referendum.
"Whether it's been fighting for the 40-hour week, equality in women's pay, Social Security, or good retirement for workers, [unions] have always been out front in every fight, because it's the right thing to do," Hall said.
Kirschner wonders about the strategy: If unions and their coalitions succeed in raising New Jersey's minimum wage with automatic cost-of-living increases, workers may not respond by rushing to join unions, he said.
They may decide, he said, that unions aren't necessary. "If the minimum wage goes up whether I am in the union or not in the union, then what are unions going to do for me if I pay hundreds of dollars in dues?" he asked.
The Service Employees International Union (SEIU), known for unionizing janitors and security guards, has provided technical assistance to the striking fast-food workers and to efforts by a faith coalition to get higher wages for skycaps at Philadelphia International Airport.
"I think organized labor is at a critical place," said Dwayne Royster, pastor at the Living Water United Church of Christ in Northeast Philadelphia and the head of the coalition.
"I think unions are a positive influence in America and I'm horrified by the negative anti-union rhetoric and influence that is taking hold in this country," he said.
In Wilmington, SEIU got involved when one of the Burger King employees learned about other fast-food strikes online and signed a website petition.
An SEIU organizer stopped by the restaurant, meeting workers in the parking lot. The workers agreed to join the nationwide strike, with SEIU providing media help and a lawyered strike notice delivered to the restaurants.
Ben Hunter, 42, a Burger King cook who participated in the one-day strike, isn't too worried about whether he and other fast-food workers are simply being used as pawns in a publicity drive to increase union visibility.
"With this job right now, we are pawns," he said. "The pawn is the lowest piece on the chessboard. If we're being used in that way, then it's good that we are being used. Unions need to make a comeback."
Contact Jane Von Bergen at email@example.com, @JaneVonBergen on Twitter, or 215-854-2769. Read her workplace blog at www.philly.com/jobbing.