Moving on up: Can the American Dream still become a reality today?

Nevada, for example, measures high in income but poor on other scales such as violence and on-time-high-school-graduation rates and so has an opportunity score of 21.3 on the index (100 being perfect), Edwards says. By contrast, Minnesota does well in multiple areas and scores 81.2. Utah's score is 75.6.

The complexity of the factors affecting opportunity and economic mobility also come into play with African-Americans. Sixty-eight percent of blacks in the middle of income distribution have downward mobility into the bottom two-fifths of income, according to the Pew study. Only 30 percent of whites fall from the middle.

"There are a lot of African-American families that are secure, that are in the middle to higher income distribution, but the neighborhoods in which they live and the environment in those neighborhoods actually increases rates of downward mobility," Currier says.

Policy and politics

Accurate statistics about opportunity can help lead to better laws and programs, Currier says. "Without good data, policymakers will not be able to implement good policy."

She says economic mobility is an extremely unifying and nonpartisan concept.

"There is so much talk about how toxic the political environment is … but our experience with this project has been the opposite," she says. "The American public believes in the American Dream — and believes that there is a role for government to play in promoting opportunity. And policy makers from across the political spectrum also cite economic mobility as an important goal for policy for the nation as a whole. I feel hopeful about that."

Back in West Valley City, McDaniel says he is optimistic that people still have opportunity. "But it takes a lot of work and motivation," he says. "I'm not sure everyone will do it. It isn't just opportunity, it is people taking advantage of opportunity."

When he was a kid, McDaniel's American Dream included three things.

"First, I was never going to drink powdered milk again and no more of that stupid puffed wheat cereal," he says. "Second, my house needed to have a garage. And third, I had to have air-conditioning."

McDaniel travels back up the economic ladder to his modest home in a nice West Valley City neighborhood. The drive is short, but the direction is what makes the difference. The grass is greener in the cul-de-sac. The playsets and in-ground trampolines are in the backyards. The fences are wood or cinder block. Cars are parked, for the most part, in garages. And air-conditioners hum like cheerful cicadas in the summer heat.

In some ways he is still the same person for whom his mother sacrificed so much. Like her, he believes in education and the possibilities that come from hard work. But he no longer sleeps on the couch and he doesn't leave the door open at night.

"I lock the doors," he says, and then adds with a laugh, "I lock them in the day."

Email: mdegroote@desnews.com, Twitter: @degroote, Facebook: facebook.com/madegroote