The Bernie Sanders campaign is the latest and largest wave of a rising populist tide, gaining force from the Occupy movement, the Dreamers, Black Lives Matter, the Fight for $15, the Wisconsin showdown, and more. The failure of the political establishment has been exposed, but the center still holds.

So what’s next? First, Sanders is right: Beating Donald Trump is vital to ensuring that bigotry and nativism do not poison and discredit the new populist moment. Once Trump has been defeated, the progressive movement should focus on defining issues and politics from the bottom up. The next movement waves—climate change, student debt, protests against systemic inequality and brutal policing—will continue to shake the establishment. Battles over these defining issues will deepen the understanding that there is an alternative. At the national level, this will start with a pitched battle over the Trans-Pacific Partnership in the lame-duck Congress, followed by challenges to the Wall Street–Washington revolving door in executive appointments, as well as skirmishes over real immigration reform, fair taxes, and rebuilding America.

In states and localities, the Sanders movement should join with insurgents in communities of color to drive real change—campaigns to establish a living wage; to save public schools; to make clean-energy, clean-water, and mass-transit investments, paid for by taxing the rich; and to enact sweeping criminal-justice reform. Those fights will set up insurgent candidates to challenge those standing in the way, from city councils to the statehouses to Congress.

Many flowers will blossom from the energy unleashed by the Sanders campaign. The Vermont senator would be well-advised to create a vehicle both to drive these defining-issue battles, and to identify and support Sanders Democrats up and down the ballot. Wherever possible, these Sanders Democrats should take control of state parties. Then we can begin to reshape how our democracy actually works.

This article originally appeared in The Nation as a part of its essay series, “We Still Need a Future to Believe In.”

This blog originally appeared in ourfuture.org on July 19, 2016. Reprinted with permission.

Robert Borosage is a board member of both the Blue Green Alliance and Working America.  He earned a BA in political science from Michigan State University in 1966, a master’s degree in international affairs from George Washington University in 1968, and a JD from Yale Law School in 1971. Borosage then practiced law until 1974, at which time he founded the Center for National Security Studies.