The liberal senator, who is reportedly mulling a second bid for the White House for the Democrats, apologised for the mistreatment during a news conference to discuss prescription drug prices.
“It appears that as part of our campaign, there were some women who were harassed and mistreated — I thank them from the bottom of my heart for speaking out”, Mr Sanders said. “What they experienced was absolutely unacceptable and certainly not what a progressive campaign or any campaign should be about”.
Mr Sanders was responding to a question about a Politico report containing allegations that Robert Becker, an operative who worked for the Sanders campaign in Iowa and Michigan, forcibly kissed a subordinate who had previously worked with him. Mr Becker denies the allegations against him.
“When we talk about — and I do all the time — ending sexism and all forms of discrimination, those beliefs cannot just be words," Mr Sanders said. "They must be based in day-to-day reality and the work we do, and that was clearly not the case in the 2016 campaign”.
Earlier this month, Mr Sanders had expressed regret over a New York Times report in which several female employees from the 2016 campaign alleged sexual harassment, disparities in pay and a workplace environment they described as either uncomfortable or inappropriate
Mr Sanders mounted a surprisingly successful campaign for the Democratic nomination in 2016 against former Secretary of State Hillary Clinton, who went on to win the nomination but lose in the general election to President Donald Trump.
Two years after that election, Mr Sanders is reportedly considering another run for the office to try and see his progressive politics implemented from the White House out.
But, a second run for the White House would see Mr Sanders joining a much larger pool of candidates running for the Democratic nomination, including candidates who appear closer to his politics than Ms Clinton was in 2016.