In the years since Somerville officials began pushing to open the first supervised drug consumption site in Massachusetts, City Council President Matthew McLaughlin says he has heard an increasingly common refrain from opponents: “We don’t want another Mass. and Cass.”

But to McLaughlin, the snowballing crisis of addiction and homelessness at the intersection of Massachusetts Avenue and Melnea Cass Boulevard in Boston makes the exact opposite case.

“Mass. and Cass exists right now, and it’s exactly why we need new thinking on how to address this problem,” McLaughlin told legislators at a hearing Monday. “The problems that people fear with safe consumption sites exist right now with no supervision at all. There are unsafe consumption sites all over the commonwealth, all over the state and the nation where people are openly using drugs with no medical assistance, no resources, nothing to prevent overdoses or help people get off drugs.”

Doctors, addiction experts, and community advocates have been arguing for years that Massachusetts needs dedicated facilities where people can use drugs – acquired on their own – under the watch of medical professionals, who would revive them after possible overdoses, prevent disease transmission, and try to connect those caught in the throes of addiction with treatment.

The idea has earned support from President Joe Biden’s nominee to serve as US attorney in Massachusetts and from a panel chaired by Gov. Baker’s top health and human services deputy, but it has yet to gain momentum among legislative leaders or Baker himself amid concerns that embracing supervised consumption sites would violate federal law.

“They’re obviously extremely controversial within the addiction community,” Baker when asked about the issue on Monday afternoon. “I would much rather put people into treatment, and I think that should be our primary focus.”

While neither House Speaker Ronald Mariano nor Senate President Karen Spilka endorsed supervised consumption sites, they both signaled Monday in the wake of a lengthy committee hearing that they might be open to the proposal.

“It’s my belief that we’re still in the middle of a crisis situation, an opioid crisis, so right now, I’m willing to take a look at just about anything that will help improve the situation,” Mariano said. “I’m anxious to hear the pluses and the minuses around the debate about a site.”

“The hearing just occurred on it, so I also am looking forward to hearing from the chairs and the members as to what they hear for the most recent, up-to-date statistics and information about it,” Spilka added. “I know it’s been successful in some countries. There are many members that want to go forward with it, so I’m looking forward to hearing the information that was gleaned at the hearing today.”

In February 2019, after then-US Attorney Andrew Lelling indicated he would pursue “federal enforcement” against any such site, Baker said he would rather “focus on the stuff that we can do now. Chasing something that’s not legal under federal law just doesn’t make a lot of sense.”

Lelling, a Trump appointee, stepped down at the end of February, and his departure could portend a major shift on the issue. Biden’s pick for the next US attorney, Suffolk County District Attorney Rachael Rollins, has been willing to try new approaches in law enforcement and has been on record for years as a supporter of safe consumption sites.

“Investing resources in evidence-based solutions, such as safe consumption sites, isn’t just the right thing to do; it’s the smart thing to do,” Rollins wrote to lawmakers in October 2019 voicing support for a pilot program.

Rollins will need to secure confirmation from the US Senate to take the reins as the Bay State’s top federal prosecutor. On Thursday, the Senate Judiciary Committee postponed for one week its scheduled vote on Rollins›s nomination.

She is not alone among Massachusetts district attorneys supporting supervised consumption sites. Berkshire County District Attorney Andrea Harrington on Monday said the facilities are “empirically proven to save lives.”

The most recent annual overdose death numbers increased 44 percent in Berkshire County, compared to 5 percent in the rest of the state, Harrington said.

“My community’s community-based prevention services and our EMS providers and our police are asked to pick up the pieces reactively,” Harrington said. “We are asking the Legislature to be proactive, to help our communities implement strategies that save people and protect public health.”

Legislation before the Mental Health, Substance Use and Recovery Committee (H 2088 / S 1272) would launch a 10-year pilot program establishing at least two supervised consumption sites in Massachusetts, regulated and licensed by the Department of Public Health.

Sterile injection supplies would be provided at the facilities, where personnel would be available to administer first aid in overdose cases and help users access addiction treatment services.

The committee advanced a similar bill last session, but it died without a vote in the Joint Committee on Health Care Financing. The Senate also included pilot program language in an opioid response bill three years ago, but House negotiators did not agree to the measure and it did not feature in the final law.

Over more than five hours of testimony on Monday, supporters and a handful of opponents aired their cases to lawmakers, warning that the state is foregoing a chance to save lives through its inaction.

Dr. James Recht, a psychiatrist specializing in addiction treatment, said many cities that open supervised drug consumption sites saw a decrease in overdose death rates and public drug use while the facilities helped connect a higher share of individuals using drugs to supportive services.

“It takes time for people with substance use problems to get into treatment. It takes time to gain insight. It takes time to overcome shame, and time is being cut short by opioid overdoses,” Recht said, videoconferencing into the hearing while doing outreach on the streets of Boston. “This is true more than ever now with the prominence of synthetic, high-potency opioids like fentanyl. They cut time short.