A “Support Noah’s Law” button is worn during a Mothers Against Drunk Driving news conference on ignition interlock devices in Annapolis, Md., in February. (Ricky Carioti/The Washington Post)

Maryland House Speaker Michael E. Busch (D-Anne Arundel) pulled Del. Joseph F. Vallario Jr. (D-Prince George’s), the chairman of the House Judiciary Committee, aside after a recent caucus meeting.

He bluntly told the chairman to stop blocking the long-sought bill that would expand the use of interlock ignitions for serious drunk drivers.

Move it, Busch said. And move it quickly.

“I told him that the House of Delegates was obligated to vote on it early in the session,” Busch said. “He took that to heart.”

Vallario, a defense lawyer, has refused since 2009 to move the same bill out of his committee. But this week, fueled by the highly publicized death of a Montgomery County police officer who was killed by a drunk driver while on DUI patrol, Maryland lawmakers are poised to approve the measure.

With officer Noah Leotta’s parents watching, the House Judiciary Committee voted unanimously late Thursday night to expand the use of interlock ignition. Under the bill, motorists convicted of driving at or above the state’s legal blood alcohol limit of 0.08 percent would be required to breathe into a tube before they can try to start their vehicles. Under current law, ignition interlocks are placed on the cars of people convicted of driving with a blood alcohol content of 0.15 percent or higher.

Lawmakers and advocates said Friday that the advocacy of Leotta’s parents and law enforcement officials, the 2014 drunken-driving death of Thomas Palermo, a cyclist hit by an Episcopal bishop, and the increased public awareness of drunken driving appeared to be the tipping point this year for what is now dubbed “Noah’s Law.”

“I think there was a measure of understanding that this was not an issue that could just be put in a drawer at this point,” Del. Benjamin F. Kramer (D-Montgomery) said, “that it needed to be addressed and it needed a vote.”

Kramer said the media coverage of Leotta’s death spurred legislative support and action. Leotta, 24, was on duty at a drunken-driving checkpoint when he was struck and fatally injured by a vehicle whose driver was intoxicated and had previous drunken-driving convictions.

“I think the media spotlight on the subject has elevated the level of awareness with the public and my colleagues here in the legislature that this was the year that we had to take some action,” he said.

Del. Kathleen M. Dumais (D-Montgomery), vice chairman of the Judiciary Committee, said the drunken-driving deaths resonated with lawmakers.

“It is certainly unfortunate that tragedies move things forward,” she said. The drunken-driving deaths “led all of us to really take a look at this.”

And yet, there were several times during the 70-minute discussion on the 42-page bill that made observers wonder if the bill actually would move.

Three delegates asked to push the vote to another day.

“I’m a little foggy,” one delegate said.

“It is late,” another argued.

Vallario refused.

“We’ve got to go through with it,” Vallario said. Alexandra Hughes, Busch’s chief of staff, sat in the front row of the hearing room.

Jan Withers, the former national president of Mothers Against Drunk Driving who has fought for the interlock bill in Maryland since 2009 and sat next to Leotta’s mother, Marcia Goldman, was stunned.

“He surprised me,” Withers said. “But that’s fine. I’ll take it. Happily so, I’ll take it.”

For years, Withers, who lost her 15-year-old daughter, Alisa, in 1992 at the hands of a drunk driver in Prince George’s County, has left the Judiciary Committee hearing room angry in the past because Vallario repeatedly refused to allow the committee to vote on the bill.

The first year the bill was introduced, it made it out of the Senate. She said the votes were there to clear the House, but it never made it to a floor vote because it could not clear committee. The same thing happened last year, she said.

“It’s been very frustrating,” Withers said.

On Thursday, a little after 10 p.m., she walked out in tears, elated that the measure had cleared such a significant hurdle.

Advocates on Friday were poring over the amendments made to the bill to ensure that the goals of the legislation remained intact.

Kramer said Friday that he planned to talk to Busch and some members of the committee about provisions he wants to address before the bill is brought to the House floor.

One of the amendments that trouble advocates is the removal of a provision that sought to require ignition interlocks for suspected drunk drivers who refuse to take the alcohol breath test. The removal creates a loophole that Kramer said needs to be fixed.

Meanwhile, Rich Leotta, Noah’s father, praised the committee, including Vallario, for passing the bill.

“I think they worked hard, Chairman Vallario worked hard,” Leotta said. “It’s not perfect, but they acknowledged that [it] needed to be done.”

Leotta said he knows his work is not done yet. He will return to Annapolis next week to testify before the Senate Judicial Proceedings Committee. And as many times as necessary until the bill is signed into law.