Sen. Bernie Sanders (I-Vt.) announced plans Monday to campaign with Rob Quist, the banjo-strumming populist Democrat running for Montanas open seat in the U.S. House of Representatives.

Rob Quist is the only person in this race who understands that we need a government in Washington that works for all Montanans and all Americans and not just the special interests and the billionaire class, Sanders said in a statement. I look forward to campaigning with him in May and working with him in Congress.

Quist, a legendary folk musician who co-founded the Mission Mountain Wood Band , won his partys nomination in March after barnstorming the state, encouraging supporters to organize Democratic committees in counties long dominated by the GOP . He defeated a handful of state legislators to win the nomination for the special election called for May 25 after Ryan Zinke, who had won re-election for the House seat, became President Donald Trump s secretary of the interior.

Until recently, top Democratic officials had largely ignored the Montana campaign, even as voters clamored for the party to focus on down-ballot races that could flip historically red congressional seats.

But Sanders organization, Our Revolution, recently endorsed Quist. And earlier this month, the Vermont senator, who caucuses with the Democrats , told The Huffington Post hed offered to make a stop in Montana on his national tour with Democratic National Committee Chair Tom Perez sometime after Easter.

The campaign has yet to announce dates for Quists appearances with Sanders, but voters can sign up with their contact information to receive alerts.

Im excited that Bernie Sanders recognizes that our grassroots campaign is building momentum and has the best chance in decades to take back Montanas U.S. House seat for the rest of us, said Quist, who endorsed Sanders in the Democratic presidential primary last year, in a statement. In the U.S. House, Ill be a voice to protect our public lands, fight for working families, work for better health care, and stand up to Wall Street and special interests.