First District Cook County Commissioner Brandon Johnson has formally thrown his support behind Sen. Elizabeth Warren in the Democratic presidential primary race. Johnson announced his decision in a statement released on Aug. 28.

During an interview on Aug. 29, Johnson — an outspoken progressive who narrowly defeated former commissioner Richard Boykin — said he was persuaded to support the Massachusetts senator because of her genuine outreach to the black community.

“She was very much interested in not just listening to black families in Chicago and Cook County, but also listening to black leaders and essentially checking her math,” Johnson said. “She checked how her plans line up with the real conditions that people endure.”

Johnson said he met with other candidates in what is turning out to be a five-person race (along with Warren, former vice president Joe Biden and Vermont Sen. Bernie Sanders are the only candidates polling above single digits while California Sen. Kamala Harris and South Bend Mayor Pete Buttigieg round out the second tier of candidates in terms of polling and fundraising, according to Politico).

Johnson said he also had conversations with Sanders, “but the only candidate who took special interest in black progressive voices was Sen. Warren,” he said. “She actually took the time to engage with us, listen to us and make some commitments to us.”

The commissioner, a Chicago Teachers Union organizer who is an outspoken proponent of Medicare for All and the expansion of mental health services, said that Warren is aligned with those positions.

Warren co-sponsored a Medicare for All bill introduced by Sanders, but has been less outspoken than Sanders in her support for a full-blown transition from Obamacare, which includes privatized insurance, and Medicare for All, which would essentially get rid of privatized insurance.

And in May, Warren reintroduced legislation that would “increase oversight and enforcement to ensure that insurance companies cover behavioral health benefits and services on par with physical health benefits and services,” according to Warren’s senate website.

“Having federal intervention around services for individuals who need treatment for their mental health is very strong and I appreciate that from her,” Johnson said.

Johnson added that he’ll be campaigning throughout the Midwest and other parts of the country for Warren. Before he officially endorsed her, Johnson introduced Warren at a town hall she held in Chicago in June.

During the Aug. 29 interview, Johnson said that, as much as he’s committed to getting Warren elected president, he’s also committed to holding her accountable.

“She’s said out loud and repeatedly that we have to continue to organize after we elect her and that’s a message that not enough elected officials will communicate,” Johnson said.