U.S. Sen. Bernie Sanders, a Vermont independent, has endorsed the Massachusetts ballot question that would mandate specific nurse to patient staffing ratios.

Sanders, who ran as a Democratic candidate for president in 2016 on a platform of universal health care, released a statement Sunday taking a position on ballot questions in several states, including Question 1 in Massachusetts.

"Nurses are the backbone of our health care system. They are there with us when we are born, when we are sick and in the last years of our lives," Sanders said. "They must be allowed to do the quality work that they have trained for."

Sanders continued, "Question 1 would set a safe maximum on the number of patients nurses can treat, so that patients can receive the quality care they deserve. Nurses are behind this initiative, and I trust them when it comes to knowing what is best for their patients."

Supporters of Question 1 say mandating nurse staffing will ensure that care is equal around the state and that nurses do not have more patients than they can safely care for. Opponents say the staffing ratios are too rigid and inflexible, and the added cost will require hospitals to shut beds and units.