Rising wealth and income inequality is a threat to democracy, Hillary Clinton said in an interview published Tuesday in the magazine Der Spiegel. Clinton was responding to a question about the recent best-selling tome "Capital in the Twenty-First Century," written by French author Thomas Piketty and translated into English.

Piketty argues that over time capital has grown faster than income from labor, which Clinton translated as society devaluing work. Clinton said she hasn't yet read the book but has read "long essays about it" and understand the thesis.

"I think he makes a very strong case that we have unbalanced our economy too much towards favoring capital and away from labor," she said. "And I agree with his principal concern, which is that we have devalued labor."

The German magazine noted to Clinton that "Piketty argues that the growing gap between the rich and the poor is threatening democracy."

Clinton seconded the notion. "I do agree with that," she said. "We've had this huge experiment known as America that was a diversity of populations, and we have held it together because we had a democracy that slowly over time included everybody. Even during the Great Depression people in the streets believed that they could make it and they would be better off. Now the relative wealth is much higher, but the disparity makes people believe that they're stuck. They no longer believe that things are going to get any better, no matter how hard they work. People have lost trust in each other and the political system and I think that's very threatening to democracy."

At the recent Aspen Ideas Festival, Clinton hit on a similar theme, arguing that if people don't believe they have a stake in the future of the country, they lose trust in the political system.

Clinton, a former first lady, New York senator and secretary of state, is mulling a bid for president. Sen. Elizabeth Warren (D-Mass.), who is seen as a potential rival to Clinton, appeared in Boston recently for a joint interview with Piketty.

Sign up below to get an email when Ryan Grim publishes a new story