He points to the Great Depression as an example. In 1928, on the eve of the Great Depression, the top 1% of Americans took in 23.9% of the nation's income. The rich ruled. (In 2007, on the eve of the Great Recession, the 1% took in 23.5% of the nation's income, according to a University of California Berkeley study.)
In 20 years, though, a political movement arose that "totally" transformed the nation, he says. A "New Deal" coalition led by President Franklin D. Roosevelt introduced a series of reforms to protect Americans from the worst features of unrestrained capitalism. They created Social Security, strong banking regulations, raised taxes on the rich and protected the rights of unions to organize.
The New Deal is a classic example of the weak and powerless -- out of work Americans standing in bread lines -- triumphing over the fierce resistance of many of the wealthiest and most powerful elites in America who dismissed the New Deal as socialism and class warfare.
Pizzigati calls the New Deal an "egalitarian triumph."
He says most Americans in the "Roaring '20s" seemed to accept the economic inequality of that time. Few people thought anything could change, and the courts often ruled against any attempts to protect ordinary workers from workplace injuries and low pay.
Yet that same generation rose up to make the New Deal a reality, he says.
"As dark as things may seem at a given moment," he says, "things can change very rapidly when a social movement takes off."
Sometimes there is no cataclysmic event that inspires people to risk it all to join a movement. It can be the steady buildup of humiliation as people stew over being treated as second-class citizens.
Consider the gay and lesbian movement for equality. Palmer, author of "Healing the Heart of Democracy," says that for years, many gay and lesbians suffered in silence as people denigrated their humanity. That changed when a critical mass decided that the pain of "behaving on the outside in a way that contradicts the truth" that they held inside was too much.
"They redefined punishment," Palmer says.
"The redefinition goes like this: No punishment anyone can lay on me can possibly be any worse than the punishment I lay on myself by conspiring in my own diminishment."
4. Divide the elites
It's easy to demonize "The Man" if you're talking with friends in a late-night dorm room rap session. But you're going to need "The Man" if you're going to beat "The Man," some historians say.
"Movements at some point have to get support from the elites," says Kazin, the Georgetown historian. "You need legitimation. You need some authorities to sort of say we may not support everything you're doing but basically you're in the right."
The civil rights movement got that support from the elites when the Democratic Party backed a civil rights bill during its convention in 1948, even though Southern white Democrats walked out, Kazin says.
Five years later, another group of elites lent their support to the movement. The U.S. Supreme Court ruled that the separate but equal doctrine was unconstitutional in Brown vs. Board of Education.
"The Supreme Court unanimously said that segregation was wrong," Kazin says. "They had an impact."
A movement, though, can't appeal to the altruism of elites to get their support. Elites help movements when they feel their own interests are threatened, says Pizzigati, author of "The Rich Don't Always Win."
That cold calculus among the rich is what made the New Deal possible, he says.