"Somebody has got to step up and fight for what is right," Allen said.
Less than a mile away from the Serene Avenue store, another shopping center stands deserted, in desperate need of an anchor.
A year ago, the Raley's grocery store here drew thousands of shoppers who spilled out to neighboring businesses, buying flowers, mailing packages, getting their nails done. Today, the store is gone. The remaining shops are struggling.
"I'm probably down 45%," said Bonnie Neisius, who owns a UPS Store franchise in the center. "I just don't get the foot traffic anymore."
A few doors away, Windmill Flowers owner Diana I. Murphy leaned on a table where she would have been arranging bouquets — had there been customers.
"There are a couple of things in play," Murphy said. "The recession, terrorism. And Wal-Mart. It's had a direct effect on me, because they sell flowers, too . They even deliver."
Unlike small towns with boarded-up commercial centers, fast-growing Vegas quickly loses track of its Wal-Mart victims.
Wal-Mart's costs to the community tend to show up in subtler ways.
In an informal survey in the late 1990s of people who used Las Vegas emergency rooms for routine medical care, patients who said they were employed but uninsured were asked where they worked.
"Wal-Mart came up more than any other," said Dr. Raj Chanderraj, a Las Vegas cardiologist and chairman of the Clark County Health Care Access Consortium, a group that works to provide medical services to the uninsured.
The reason, say critics: Because Wal-Mart pays such low wages, many employees can't afford the health insurance the company offers. And those who do have health coverage through the company often can't afford deductibles that run as high as $3,000 a year.
"Their employees are ending up at the county hospital and become the burden of the county," said Clark County Manager Thom Reilly.
Wal-Mart disputes that. Williams, the company spokeswoman, said that 48% of employees are covered by Wal-Mart's health insurance plan. Among those who aren't, 26% have coverage from another source such as a spouse's employer or Medicare, Williams said.
The notion that Wal-Mart doesn't provide adequate health coverage is "just rhetoric," she said. "It's simply not true."
According to the Employee Benefit Research Institute in Washington, nearly 44% of workers in the retail sector as a whole have employer-provided health coverage. Among big companies in all industries, the figure is 66%.
Those who accuse Wal-Mart of shortchanging its employees, Williams suggested, don't understand the modern service economy. "Retail and service wages are what they are," she said, "whether you look at a department store, a discount store, the local dry cleaners, the bakery or whatever.
"Wal-Mart is a great match for a lot of people," Williams added. "But if you are the sole provider for your family and do not have the time or the skills to move up the ladder, then maybe it's not the right place for you."
'I Still Believe in Wal-Mart'
Larry Allen spent about a year advocating for the supermarket union while working at Wal-Mart.
In the parking lot and in the break room, he passed out fliers and talked up the benefits of unionizing. But he and his fellow union backers didn't get as far as they hoped. About 42% of workers in the grocery department at Serene Avenue signed UFCW cards — not enough for the union to feel confident about winning an election.
In August, Allen was fired. NLRB attorneys said it was because of his union activities and filed a complaint against Wal-Mart, seeking his reinstatement.
On a recent afternoon outside the Supercenter, dozens of union members rallied to support Allen. "Larry, Larry, Larry," they chanted. Over at the store entrance, the demonstration was a muffled, distant bit of noise. Store managers watched on a screen as surveillance cameras scanned the crowd.
Asked about the commotion, a gray-haired Wal-Mart greeter named Robert just smiled. "They want to make the store union," he said. "But that would make the prices go up for our customers. We can't let that happen."
On some level, even Larry Allen understands. "I still believe in Wal-Mart," said Allen, who now is on the union payroll as an organizer. "I like the idea of it — give a quality product at a low price. It's what the American public wants."