While both presidential candidates and their running mates have lauded small business as the backbone of the U.S. economy, pledging tax breaks and other enticing benefits for owners, while doing their best to win the vote of a certain plumber from Ohio, only one has touted first-hand, small-business experience -- Alaska Gov. Sarah Palin.

On Friday, during her first on-camera press conference, the Republican vice presidential candidate fielded a question about her qualifications by listing her executive experience "as coming from a mayor and manager, small-business owner and a governor, and a regulator of oil and gas."

It's become something of a familiar refrain for Palin on the stump. During her debate with Sen. Joe Biden earlier this month, she listed her experience "as a mayor and business owner" among the skills and resources she brings to the Republican ticket, before a television audience of 70 million.

While her tenure as mayor of Wasilla, Alaska, is now well-known, Palin's credentials as a small-business owner are less clear. Judging by recent tax data and a public financial disclosure form required of all federal candidates, her experience appears to be limited to a supporting role with a handful of modest ventures, including Toad's Fisheries, her husband's commercial fishing operation, and a now-defunct carwash, among others. 

The McCain campaign did not respond to repeated requests for information regarding Palin's small-business experience.

What's certain is the vice-presidential debate wasn't the first time on the campaign trail that Palin sought to identify herself with the nation's 27 million small-business owners and the millions more they employ. At a stump speech in Cedar Rapids, Iowa, last month, Palin spoke of her family's "commercial fishing business," as well as her sister's gas station and her in-law's hardware store.

Two days earlier at a rally in Golden, Colo., she described the fishing business as a shared enterprise with her husband, Todd Palin, saying "my husband Todd and I, we have a commercial fishing operation."

"We've all built small businesses and worked hard to earn a living," Palin told the crowd. "We know the struggles out there."

Toad's Fisheries sells salmon caught in Bristol Bay to a commercial buyer in Seattle. Last year, the business made $15,513 in profits, with a gross income of $49,893 offset by $32,979 in expenses, the couple's joint tax return shows. The previous year was even leaner, raising $7,690 after expenses. Both returns name Todd Palin as proprietor and the couple's Wasilla home as a main office.

On her public financial disclosure form, Palin describes the business as a sole proprietorship owned by her husband, listing the type and amount of proceeds simply as "Fishing Income."

Of course, the low payoff isn't unusual for the fishing industry. According to the commercial fisheries division of the Alaska Department of Fish and Game, permits alone for entry into the state's limited-access fisheries can run from $8,000 to $450,000, with payments on a 10- to 15-year schedule. That's on top of rising costs for fuel, nets, and other gear. "You can appreciate the tremendous overhead involved," the agency says on its Web site.

The couple's taxes also list several thousand dollars in sponsorship proceeds from Todd Palin's snowmobile racing career, though these were also largely offset by expenses.

In both cases, the businesses are filed in a Schedule C form under Todd Palin's name as sole proprietor. According to Barbara Weltman, a New York-based small-business tax expert, that means Sarah Palin isn't technically a small-business owner -- at least for tax purposes.

"If it were a husband-wife partnership, than each would have filed a Schedule C to report their share of profits and on which each would figure self-employment tax," Weltman said.

Carmen Bianchi, a family business expert at San Diego State University, says it's not a stretch for Palin to call herself a small-business owner.

"It's fairly typical for family businesses to file in this way," Bianchi says about the couple's income tax returns.

Still, Palin's business dealings don't end there. A few years ago, the couple each invested a 20 percent stake in a local carwash that public records show never got off the ground. In April 2007, the state division of corporations, business, and professional licensing issued an involuntary dissolution of the registered business, which had long since been sold off and abandoned.

Palin's gubernatorial financial disclosure filings also show she secured a license for a consulting firm tentatively called "Rouge Cou," a literal French translation of "redneck." Like the carwash, the venture was never pursued and the license eventually expired.

Given that the Republican VP nominee has spent most of her adult life as a full-time public official -- as a small-town mayor and later as a state governor -- it's not surprising her involvement with these businesses is limited, if only from a time-management standpoint.

Yet, bona fide or not, Washington insiders are mixed on how Palin's small-business experience will play with voters.

"It's always nice to have someone with hands-on small-business experience, albeit in a supporting role," says Andrew Sherman, a small-business policy expert at Dickstein Shapiro, Morin & Oshinsky, a Washington-based law firm. "I assume she will be small-business friendly, given her conservative politics."

That said, Sherman adds he's yet to hear specific policies from either the McCain or the Obama camps regarding the Small Business Administration or research and development programs, or other topics owners consistently identify as important to them.

George Cloutier, the CEO of American Management Services, an Orlando, Fla.-based small-business consulting firm, says regardless of Palin's background as a small-business owner, it hasn't translated into policy.

"None of the candidates would know a small business if they tripped over one," Cloutier says. "Joe Biden has absolutely no small business experience, neither does Barack Obama or John McCain. Palin has maybe a little experience, but it's total pablum."

Despite those shortcomings, Cloutier, who in 2003 was named the nation's top small-business advocate by the U.S. Conference of Mayors, says voters seem to like Palin's style and that her identification with small-business owners was a plus for the McCain ticket.

"I suspect it's pulling a few independents towards her column," he says.

But a McCain-Palin victory could be bad news for Toad's Fisheries. Under Barack Obama's tax plan, which would raise the tax rate a few points for businesses earning a net annual income of over $250,000 after expenses, the Palins -- along with "Joe the Plumber" -- would be eligible for a tax cut.