Throughout his campaign, Senator Bernie Sanders has made the breakup of big financial institutions a central theme.

But in an interview with the PBS NewsHour which airs tonight, Judy Woodruff pressed Sanders on arguments from experts who say federal regulators already have the power to break them up, but think the existing system is safer.

Sanders responded by saying shrinking “too-big-to-fail” banks is not just a matter of reducing risk to the country — it’s a matter of targeting the power the banks hold. Sanders says six of the largest banks have assets totaling 58% of U.S. gross domestic product, and it’s time to create a financial system where power is not just concentrated in the hands of a few banks.

“Now is the time, I think, and a critical moment in American history, for our people to come together and tell the billionaire class, and tell Wall Street, and tell their apologists that we do need a government that works for all of us, not just a handful of wealthy campaign contributors,” he said.

You can watch the full interview on the PBS NewsHour tonight.