RICARDO ARDUENGO/AFP/Getty Images Sen. Bernie Sanders (I- Vt.) talks to the Mayor of San Juan, Carmen Yulin Cruz during a visit to the Playita community in San Juan, Puerto Rico, on October 27, 2017.

Sen. Bernie Sanders (I-Vt.) tapped Rep. Ro Khanna (D-Calif.), San Juan, Puerto Rico Mayor Carmen Yulín Cruz, former Ohio state Sen. Nina Turner (D) and Ben Cohen, a co-founder of Ben & Jerry’s ice cream, to serve as co-chairs of his presidential campaign.

Cohen, a Vermonter, and Turner, who is president of the Sanders-backed political nonprofit, Our Revolution, are veterans of Sanders’ 2016 presidential run.

But the addition of Khanna and Cruz reflects the degree to which Sanders has expanded his influence in the years since he challenged Hillary Clinton for the Democratic presidential nomination.

What’s more, the four-person slate provides Sanders’ bid with diverse leadership, a quality that critics felt his 2016 campaign lacked. Of the group, just Cohen is a white man.

“To win this election and build a movement to defeat Donald Trump, we must bring together a team prepared to fight for economic, social, racial and environmental justice ― and that’s exactly what Nina, Ro, Carmen and Ben have been doing their entire lives,” Sanders said in a statement announcing their selection. “Together, along with a million-person grassroots movement, we will confront the powerful special interests that dominate the economic and political life of our country and enact an agenda that represents all the people, not just powerful special interests.”

The co-chairs will serve as central advisers to Sanders’ campaign, helping generate enthusiasm for his candidacy across the country, according to the Vermont senator’s campaign staff.

Khanna, in particular, is likely to play a critical role in boosting Sanders’ chances in California. The Golden State primary, where home-state Sen. Kamala Harris (D) would be a natural favorite, is slated to occur on March 3 ― much earlier than in previous primaries.

Khanna has teamed up with Sanders on legislation attempting to stop U.S. support for the Saudi war in Yemen, as well as a bill that helped pressure Amazon CEO Jeff Bezos into raising his employees’ wages.

“Every 50 years, there is someone who can fundamentally alter the course of American politics,” said Khanna, an outspoken progressive in his second term representing Silicon Valley in the House. “Bernie Sanders has the chance to reorient our economic policy towards workers and communities left behind instead of corporate interests and to reorient our foreign policy to prioritize peace, diplomacy and restraint instead of war.”

Cruz, who hosted Sanders during a trip to the island to survey Hurricane Maria recovery efforts in October 2017, shares the Vermont senator’s penchant for social democratic policies and unvarnished outrage at perceived injustice. She developed national renown in the wake of Hurricane Maria in September 2017 for her vocal criticism of President Donald Trump’s handling of the storm.

A month after his visit to the U.S. territory, Sanders proposed a $146-billion “Marshall Plan” for Puerto Rico and the U.S. Virgin Islands that would effectively wipe out Puerto Rico’s crippling public debt.

Cruz could prove an asset to Sanders in Latino-heavy Nevada, which hosts a caucus on Feb. 20, as well as in Puerto Rico and other primary and caucus states later on.

“In our darkest hour, he was there for us not because it was politically convenient but because it was the right thing to do,” Cruz said in a statement. “When it comes to Puerto Rico, I am confident that Bernie will help us usher a new path towards the resolution of many of the issues facing Puerto Rico including, but not limited to, a new relationship between Puerto Rico and the United States ensuring that with every step we forge a path to guarantee that all voices are heard and the will of the people of Puerto Rico sets forth the agenda.”

Earlier this week, Sanders made waves with his campaign manager pick. On Tuesday, the Daily Beast reported that Sanders had hired Faiz Shakir, the national political director of the American Civil Liberties Union, for the top post. Shakir is likely to be the first Muslim American to head a major presidential campaign.

The campaign has also retained Analilia Mejia, the state director of New Jersey Working Families, as its national political director, and Sarah Badawi, the government affairs director of the Progressive Change Campaign Committee, as its deputy political director.