Three senior staff members on Sen. Bernie Sanders' presidential campaign quit Tuesday because they couldn't get on the same page with Sanders on creative issues.

Tad Devine, Mark Longabaugh, and Julian Markey worked as media consultants on Sanders' 2016 campaign, and announced their departure on NBC News. Before leaving, they produced Sanders' 2020 announcement video.

Who are they? Devine was Sanders' chief strategist, Longabaugh worked closely with the Democratic National Committee and led the strategy to secure delegates, and Mulvey helped create the campaign's ads.

The three men's consulting firm, DML, earned $5.3 million from the 2016 campaign, which opened them to criticism by some Sander supporters.

What do they say about it? "The entire firm has stepped away," Longabaugh said on NBC News. "We just didn't have a meeting of the minds."

"We are leaving because we believe that Sen. Sanders deserves to have media consultants who share his creative vision for the campaign," the three men said in a statement.

What does the Sanders campaign say about it? "The campaign appreciates all the good work DML has done and wishes them well," said Sanders' campaign manager Faiz Shakir.



What else might be going on here? Sanders recently told The Young Turks in an interview (before this staff change) that he wanted to have a more diverse staff this time around.



"We have been criticized, correctly so, for running a campaign that was too white and too male-oriented, and that is going to change," Sanders said.

Devine has attracted some negative attention for having worked with former Trump campaign chairman Paul Manafort consulting in Ukraine. Manafort pleaded guilty last year to financial crimes including tax fraud and violations of foreign lobbying laws.

While the cited reason for the change was creative disagreement, a source told CNN that the departure wasn't necessarily unexpected in light of the things Sanders wants to do differently in 2020.