A college diploma is supposed to be the ticket to the good life. Colleges and politicians tell students, "Your life will be much better if you go to college. On average during your lifetime you will earn a million dollars more if you get a bachelor's degree." Barack Obama, stumping on the campaign trail, said, "We expect all our children not only to graduate high school, but to graduate college."

Rachele Percel heard the promises. She borrowed big to pay about $24,000 a year to attend Rivier College in New Hampshire. She got a degree in human development. "I was told just to take out the loans and get the degree because when you graduate you're going to be able to get that good job and pay them off no problem," she told me for last week's "20/20."

But for three years she failed to find a decent job. Now she holds a low-level desk job doing work she says she could have done straight out of high school. And she's still $85,000 in debt. This month she had to move out of her apartment because she couldn't pay the rent.

The promise about college? "I definitely feel like it was a scam," says Rachele.

Her college wrote us that that many of its graduates have launched successful careers. But Rachele's problem isn't uncommon. A recent survey asked thousands of students: Would you go to your college again? About 40 percent said no.

"The bachelor's degree? It's America's most overrated product," says education consultant and career counselor Dr. Marty Nemko.

Nemko is one of many who are critical of that often-cited million-dollar bonus. "There could be no more misleading statistic," he says. It includes billionaire super-earners who skew the average. More importantly, the statistic misleads because many successful college kids would have been successful whether they went to college or not.

"You could take the pool of college-bound students and lock them in a closet for four years -- and they're going to earn more money," Nemko says.

Those are the kids who already tend to be more intelligent, harder-working and more persistent.

But universities still throw around that million-dollar number. Arizona State recently used it to justify a tuition hike.

Charles Murray's recent book, "Real Education", argues that many students just aren't able to handle college work. Graduation statistics seem to bear him out.

"If you're in the bottom 40 percent of your high school class," Nemko says, "you have a very small chance of graduating, even if you are given eight and a half years."

Colleges still actively recruit those kids, and eight years later, many of those students find themselves with no degree and lots of debt. They think of themselves as failures.

"And the immoral thing about it is that the colleges do not disclose that!"

For many kids, career counselors told us, it's often smarter to acquire specific marketable skills at a community college or technical school, or to work as an apprentice for some business. That makes you more employable.

Vocational education pays off for many. Electricians today make on average $48,000 a year. Plumbers make $47,000. That's more than the average American earns. But some people look down on vocational school. A degree from a four-year college is considered first class. A vocational-school degree is not.

"More people need to realize that you don't have to get a four-year degree to be successful," says Steven Eilers, who went through an automotive program and then continued his education by getting a paying job as an apprentice in a car-repair center. He's making good money, and he has zero student-loan debt.

Eilers story is no fluke. In the past year, while hundreds of thousands of white-collar jobs vanished, the auto-repair industry added jobs.

Self-serving college presidents and politicians should drop the scam. Higher enrollments and government loan programs may be good for them, but they are making lots of our kids miserable and poor. For many, the good life can be lived without college.