Former President Bill Clinton sits down with CNBC's Becky Quick at the Clinton Global Initiative's annual meeting in New York on Sept. 20, 2016.

Former President Bill Clinton saw U.S. voter anger brewing.

In an interview with CNBC's "On the Money," Clinton said a few years ago he shared with his wife — former Secretary of State and current Democratic nominee Hillary Clinton — his view of the mood of the electorate.

"Way before Hillary declared, I said you've got to get prepared for this," the 42nd president told CNBC at the Clinton Global Initiative, held in New York City.

"There's a lot of populism, because there's a lot of road rage. People believe the political and economic order have let them down."

Clinton called his wife "a sort-of 'answers person' not an 'anger person.' I mean you feel anger, but, you've got to be yourself," he said. "Just go out there and try to be the grown-up in the room."

He predicted Vermont Sen. Bernie Sanders would "do well in the primary." And while Clinton "didn't know Donald Trump would be the Republican nominee," he thought he would "get a lot of votes."

The former Arkansas governor, known as a canny politician, said he "wasn't surprised" by the early primary success in many states by both Democrat Sanders and Republican Trump. Both candidacies were driven by voter anger, something he recognized because "I just saw it happening other places."