Supporters of a bill enabling people to register to vote as they cast their ballots are mounting another push for the long-sought reform as a key legislative deadline approaches and another election season unfolds in Massachusetts.

With encouragement from Attorney General Maura Healey and backing from Secretary of State William Galvin, voting reform activists launched what Common Cause Massachusetts Executive Director Pam Wilmot called a "deadline push" Tuesday asking lawmakers to advance the current "same-day" legislation (H 636, H 685, S 396) before the Feb. 5 deadline by which committees must report most bills with a recommendation.

"We want to make the case today as loud and clear as we can that it's time for election-day registration," Wilmot told the News Service after a lobby day event. "We're hopeful this will get out of committee with a favorable report. It's long past due. Twenty-one other states have done this reform. It has been working well for 40 years across the country."

Efforts to allow prospective voters in Massachusetts to register and cast ballots in one trip to their polling places have been unsuccessful for years, but advocates believe the boosted interest in a presidential election year and momentum from recent electoral reforms can help get a bill across the finish line this session.

Early voting in Massachusetts began in 2016, and as of Jan. 1, eligible residents who interact with the Registry of Motor Vehicles or MassHealth will automatically be registered to vote unless they opt out.

Massachusetts is also on track to consider a ballot question in November that would implement a ranked-choice voting system, which Galvin backs.

"As people have seen these various other proposals implemented successfully, I think the resistance is diminishing," Galvin told the News Service. "They know administratively we can handle it if it's properly done."

Galvin said the new policy could be in place for the Sept. 1 state primary or Nov. 3 general election if lawmakers act soon, but that it would be a "challenge" for cities and towns to prepare if the Legislature waits until the July 31 end of formal session to pass a bill.

"The timeline is important," Galvin said. "If they were to do it in the month of April and May, definitely, we could do it for September. If they do it in July, it will be tighter."

A coalition of organizations that attended Tuesday's lobby day estimated same-day registration could boost voter turnout by up to 100,000 in Massachusetts, which Galvin said could be accurate for the most high-profile elections.

The secretary said implementing same-day registration statewide would cost at least $1 million, but that the figure could increase if cities and towns seek funding to add precinct wardens or equipment.

Under current law, unregistered but eligible voters must register 20 days ahead of an election in order to vote in that election. The registration deadline ahead of the March 3 presidential primary is Feb. 12.

The Senate has approved same-day registration twice. In 2008, the chamber passed a same-day registration bill that did not clear the House. The Senate also added an amendment with similar language to an omnibus election reform bill in 2014; the provision was dropped during negotiations with the House.

Since then, similar bills have stalled out in committee in each of the last two lawmaking sessions.

The committee heard testimony on the latest iterations of the legislation in June. Under joint legislative rules, most committees must make recommendations on bills by Feb. 5, and formal legislative sessions end for the two-year cycle on July 31.

Election Laws Co-chair Sen. Barry Finegold said Tuesday that he personally supports same-day registration but is not yet sure if there will be enough consensus on the committee to advance the legislation by the deadline, sometimes referred to as "Joint Rule 10 Day."

"I'm hopeful we can get enough members on the committee to support it," he said. "I'm hopeful. I think it's something we should have. I think the fact that New Hampshire has it and we don't — I think it's something that would help a lot of people vote."

The committee has not polled its members on the bills, Finegold said. His co-chair, Rep. John Lawn, could not be reached for comment Tuesday.

Maine first implemented same-day registration in 1973, and since then, 20 other states have rolled out similar policies, according to the National Conference of State Legislatures. Nine of those states have implemented or enacted the policy in the last two years alone, coalition supporters said Tuesday.

Wilmot said states with day-of registration typically see 3 to 12 percent higher turnout than those without it. The largest use, both she and Galvin said, comes not from brand-new registrants but from those who move close to an election and do not update their addresses until they go to vote.

Speakers pushed back Tuesday on common arguments against the practice, saying the penalties for falsely registering are high enough to prevent fraud.

Carol Rose, executive director of the American Civil Liberties Union of Massachusetts, was among those who turned out to lobby for the voting bill. "It's a foundational right upon which all the other rights and liberties that we have rest, the right to vote, the right to have the franchise," she said. "It's why so many people have fought for so many years — more than 100 — for the right to vote."

Town clerks have raised concerns about how the change would work. At the committee's June hearing, Massachusetts Town Clerks' Association legislative agent Thomas Joyce said members did not outright oppose the bill but worried about low connectivity at polling places making it difficult to validate new voter submissions.

Healey renewed her support for the policy change at Tuesday's event, describing it as an important step to strengthen democracy.

"My office has seen over the last few years efforts to suppress the vote all around this country, to make voting that much harder for too many people," she told activists as they prepared to meet with lawmakers. "We've seen efforts that disproportionately affect low-income people, people of color, and those efforts in many respects have been intentional. That's why we need to be intentional here in Massachusetts. We need to make sure Massachusetts is at the forefront of making sure that everybody has the opportunity to vote."