(FORTUNE Magazine) – Suze Orman is on a mission. She says she's out to "change the way America thinks, acts, and talks about money." Not many people in the finance world would define their own lives, in public and without irony, as a "quest," as Orman does. She loves to talk about money, and she enjoys meeting new people, especially if they're fans. And so this spring, to promote Orman's sixth-straight-bestselling financial self-help book, The Laws of Money, the Lessons of Life, her publisher chartered a bus--the very same 45-foot, $600,000 MCI Renaissance normally reserved for Shakira, the Latin pop star, and Ozzy Osbourne, the Prince of Darkness--and sent her on a six-week 21-city tour around America.

In its mixture of service and self-promotion, it was the perfect Suze Orman event. The bus, glossy nail-polish red with a huge Laws of Money cover shot of Orman on both sides, was originally intended as a traveling billboard, with the author/TV host/guru herself following along in a private Lear 35 and sleeping in a string of five-star hotels. Everyone who works closely with Orman--her East and West Coast assistants, a publicist, and a brand manager--was sure she'd hate traveling on the bus.

She didn't. She loved it. It was spacious and comfortable and was equipped with big flat-screen TVs, and since Orman is the kind of person who travels by Learjet but eats at McDonald's and says things like "I love getting stuck in traffic!" she was in heaven.

In Chicago, on the first day of the journey, Orman had the tour manager pick up her 88-year-old mother and drive them around the South Side neighborhood where Orman grew up. By the second day she began canceling her Lear flights and hotel reservations. By the time they hit the Ozarks, Orman, who rarely drives a car herself but has to be one of the most quirkily self-confident people this side of Donald Rumsfeld, simply couldn't resist. She had to get behind the wheel.

It is exactly that triumphant, move-over-I'm-driving attitude that makes Orman, who is 52 and has a bob of frosted hair and big, eager blue eyes (as well as more than 40 pairs of eyeglasses), such a perplexing and compelling character. She is as happy at the helm of a bus as she is doling out hard and fast personal finance "laws" to millions. And her drive to spread what she calls the "message of financial freedom" has landed her seemingly everywhere.

And by everywhere, we mean: everywhere. Besides busing her message to small towns in Kansas, the Mall of America, and the Hoover Dam, Orman has also built herself a financial-advice empire. The Suze Orman Financial Co., which she runs out of an office in Emeryville, Calif., and her brand manager's San Francisco living room (which they refer to as the Clubhouse), clears around $4 million in profits a year. Suze has sold more than six million books, she hosts The Suze Orman Show on CNBC (watched by 113,000 households), and she holds the record for most books sold in an hour on the QVC shopping channel (35,000 for The Courage to Be Rich). Her PBS fundraising special places third in the network's all-time rankings, behind The Three Tenors and a Doo Wop concert but ahead of Riverdance (No. 5), Yanni (No. 6), and well beyond other self-helpers like Deepak Chopra (No. 18). She says she's worth around $20 million but rarely thinks about it. She keeps almost all her money in municipal bonds and money-market funds and recently sold her 1,000-square-foot house in Oakland for $675,000. (She bought it 20 years ago for $60,000.) She keeps a small apartment in New York City, has lived most of the past decade in hotels, and has never been married. She sells Suze's Choice long-term-care insurance through GE Financial. Currently she's planning a move into China, where the book that put her on the map in the U.S., The 9 Steps to Financial Freedom, is on sale in Mandarin.

Orman's message combines emotional and spiritual observations about money with advice on what to do with it. She is a firm believer in the healing power of the basics and in her own ability as a messenger. A great many people love her, but it must be said that Suze Orman, with her in-your-face style, drives a lot of other people nuts. Is she a reckless self-promoter? Or a motivated, financially enlightened missionary? What do you make of a person who rides around in a big red bus with her face on it, talking to people in McDonald's about revocable living trusts?

On this tour Orman brought A whole new--and rather controversial--chapter of gospel to proselytize along with her usual message that average Americans should be paying off credit card debt before they begin saving. Now she's preaching that everyone should be aggressively paying off mortgage debt as fast as possible. In fact, if you're living in a house that you're planning to stay in for a good long time, Orman says that you should go as far as to pay off your mortgage debt even before you contribute past the match on your 401(k).

Now, there are two ways to look at that idea. The first is that it is a very counterintuitive concept that could benefit a large swath of severely debt-saddled America right now. That may be true.

The second way would be that it's just more Suze Orman crazy talk, which is to say, lethal quackery that boils the blood of certified financial planners everywhere.

"Insanity!" says Gary Schatsky, former chairman of the National Association for Personal Financial Advisors. "That advice will be wrong for a large number of people. She is trying to be the Martha Stewart of personal finance, and it's dangerous. That's an insane generalization. You can always pay down your mortgage. You can't always give whatever you want to your 401(k)."

The idea that paying off the mortgage can be done anytime is part of the conventional wisdom of retirement planning: steady investments, diversified portfolios, many happy years of tax-deferred compounding, and--voila!--you're tanning in Boca. But then, what Orman is saying is something like, Yes, but what if something goes wrong?

"Today we live in a world with more unknowns than I have ever seen in my life," she says, sitting in the lobby of the CNBC building in Fort Lee, N.J. Orman tends to infuse even one-on-one conversations with oratorical intensity. "Having talked to literally tens of thousands of people, I can say that what is good for America--and not just what is good theoretically, or for some financial wizards, but what is good literally--is not having credit card debt, not leasing a car, and not having mortgage debt. This is not good for a human being. It's just not. All these financial shows spending all their time telling people what to do with their money ..." She waves her arms toward the rest of the CNBC studio. "Well, get out there and talk to people like I do. The truth is, they haven't got any money. Who has money to invest anymore? Invest what?"

Her argument does seem downright compelling. First, pay off your credit card debt. John Bogle, founder of The Vanguard Group and patron saint of prudent investing, heartily agrees with that. "It's the only investment you'll find out there now with returns of 16%," he says, sarcastically referring to the average credit-card interest rate. Next, Orman says you should start saving for an eight-month emergency fund in case you lose your job. Then, once you get to be 45 or so, she says, and you're in a house that you plan to stay in, start paying off the mortgage. Not only is it the biggest monthly expense you'll have, but owning outright has other advantages. Like sanity, for instance. As far as the money you might--repeat, might--have made from the compounding in your 401(k), she says, "People who say 401(k)s are the best thing that have ever been created? Oh, give me a break. They were a very nice thing for the corporations to get out of funding their employee retirement plans."

In fact, if you've just refinanced your house and have been diligently contributing to your 401(k), imagine this: You're fired. You can't find another job for, say, a year. Your 401(k) is way down and returning less per month than your mortgage payment cost. You've got trouble.

That's not an unlikely scenario. White-collar management jobs are arguably as vulnerable today as they've ever been, and according to the Federal Reserve, national household debt has increased 66%, to $8.49 trillion, since 1995. Of course, even if you don't lose your job, you're not necessarily on the scenic route to long-term security: Companies across the country are gutting their health benefits, sometimes eliminating them altogether. (See "Your Financial Reality Checkup.") Which is why Suze wishes you would just go ahead and pay off the house already. Assuming--now that mortgage foreclosures are at a 30-year high--that you still have a house.

Meanwhile, there's that all-American tendency toward overly optimistic financial planning. As a people, we tend to max out our monthly expenses, blithely overestimating things like mortgage-interest tax deductions and underestimating broker fees and the taxes we'll eventually pay on our 401(k) savings. We have an unfounded faith in double-digit stock market returns. Warren Buffett himself is predicting no more than 6% returns in the near future, as Orman likes to point out. She also loves to mention that between 1965 and 1982, the Dow went up less than one point.

Orman admits that her mortgage idea doesn't apply to the very rich, but she does suggest that it scales up higher than you might think. How far up? "If FORTUNE readers were to look in the mirror and get honest with themselves--law No. 1--and, say, if they didn't have one penny of income coming in for the next year--how long could they make it?" she asks, winding up for another oratorical onslaught. "Could they make their mortgage payment, their car payments, and their living expenses? Their private schools and their houses in the Hamptons? Could they live? Could they? How much money do you really have in savings, ladies and gentlemen?"

It's hard to argue with the basic message: To ensure financial survival, cut expenses. "I think Orman is right to advise families to prepare for the worst," says Elizabeth Warren, a Harvard professor and co-author of the forthcoming The Two-Income Trap: Why Middle-Class Mothers and Their Families Are Going Broke. "Middle-class families are in trouble like never before. The dangers facing families are rising fast--faster than families can keep up, no matter how hard they work."

And yet for some people there is simply no getting past the messenger. Orman still displays symptoms of having lived in the San Francisco Bay Area during the hot-tub-soaking, est-following, astral-projecting 1970s. In her first job at Merrill Lynch, she took to using a shard of crystal to help her determine whether a stock would go up. (Today, she says, she's come to understand that "I was the crystal.") After she'd started her own financial-planning firm, she asked clients to deposit their checks under a statue of the Hindu deity Ganesh, the Remover of All Obstacles. Her musings on money wander between the mystical and the goofball. (Suze on fire escapes: "When I look at a house, I admire the mandatory ugly aluminum ladder that allows you to escape if your building catches fire. Most of us don't have fire escapes in our own lives. Why not? We do it for our precious buildings! Why don't we do it with our precious lives?" And on the eye-over-pyramid thing on dollar bills: "The eye represents spirituality--the third eye--and there is an aspect of money that is very emotional and spiritual. It's on a $1 bill because we need to be one with our money.")

Here are a few important things you should know about Suze and where her obsessional battle with debt began.

First, you should know that she grew up in Chicago and that her father, Morry Orman, ran a takeout chicken shack, and that on the day that it burned down, a 14-year-old Suze (then Susie--in the 1970s she changed the spelling but kept the pronunciation) watched him run back inside to rescue a scalding metal cash register. After that Morry started a boarding house, and a tenant fell off a rickety staircase and sued the family for everything it had. "From then on," she says, "everything my father did turned to dust."

That childhood experience helps explain Suze Orman's passion--why, at 52, she's still willing to ride 1,250 miles in a bus across America to crusade against what she considers our collective state of financial denial. She has seen the perils of debt first-hand and she is here to tell you about them, ladies and gentlemen.

Orman is at her most convincing when she speaks in front of a live audience, which she did earlier this May at the Kent Place School in Summit, N.J. The event was held in the school gymnasium, where there were about 500 people sitting in folding chairs on the basketball court. As Orman rose to approach the podium, two mounted speakers blared the 1989 one-hit-wonder song "I Wanna Be Rich." The crowd loved it.

She began by putting forth her no-longer-worst-case scenario: You've been laid off, your 401(k) stinks, and it's hell trying to find another job.

She leaned forward, grabbed the podium, and launched into the gist of her message: Invest in the known before the unknown. "Where are you going to invest your money today, ladies and gentlemen, to yield enough income for you to pay these mortgages on these exorbitant homes that we all own?" she asked in a pleading tone. "On these cars that we are driving that are as expensive as the little houses that we bought years ago? It's true. Where are you going to get that kind of money?"

She put an insistent hand on her hip, flipped her bangs, and made a ticking noise with her tongue. Mortgages never sounded so ominous. The audience was rapt.

"It may be fabulous for you to get a tax write-off. But if something happens to you, ladies and gentlemen ..."--and here she surveyed the crowd for a moment before delivering her punch line--"I promise you one thing: Uncle Sam is not going to let you move in with him."

That one brought down the house.