Mayor Michael R. Bloomberg may be the most outspoken elected official advocating for enhanced gun safety laws, but the New York public servant who has hands-on experience in Washington getting such legislation passed is promoting the use of smart phones to hail cabs in Manhattan.

In a prior life, New York’s taxi and limousine commissioner, David Yassky, played a major role in writing the 1994 Assault Weapons Ban, which outlawed the production of certain types of weapons and limited the size of high capacity magazines. As chief counsel to then-Rep. Charles E. Schumer (D-N.Y.) on the House crime subcommittee, Yassky had a front-row seat to the last major congressional deal on guns — in which a congressman’s eleventh-hour change of heart gave gun-control advocates a two-vote victory in the House, where Democrats were in the majority.

Although the massacre of 20 children and six adults in a Newtown, Conn., school seems to have added impetus for reconsideration of gun laws, many of the elements that Yassky says were essential for victory in the close House battle have been absent in recent years. One glaring difference between the political landscape today and some 18 years ago: Democrats no longer control the House.

In 1994, Rahm Emanuel, President Bill Clinton’s then-political director, played a key role in wrangling votes; a coalition of police and sheriff’s groups, some from gun country, who supported new gun regulation offered lawmakers political cover; and there was strong leadership in Congress.

Yassky recalled how Schumer organized an effort to find votes in each region of the country, especially among members in pro-gun districts with enough popularity to survive an erosion of support. Schumer carried a list of five colleagues to lobby every time members met on the floor. Staffers spent months in substantive talks about which guns would and wouldn’t be covered. Concessions also played a role in fashioning a deal: The agreement to require the gun control measure to be renewed — or lapse — after 10 years brought a score of votes along. The central requirement though, Yassky said, was political courage.

Look at gun homicides and gun ownership by country

“Maybe it’s obvious,” he said, “but you need some heroes from tough districts.”

In 1994, House Speaker Tom Foley (D-Wash.) hailed from a pro-gun district, as did Jack Brooks, the Democrat from gun-friendly Texas and the chairman of the House Judiciary Committee. Neither was interested in the issue, and rather than push stand-alone legislation, Schumer had to offer the ban as an amendment to then-Sen. Joe Biden’s (D-Del.) crime bill. Most Republicans opposed the measure, and those who might have been theoretically favorable were loathe to hand Democrats a legislative victory.

After months of work, Schumer felt comfortable enough that the moment was ripe for a vote. After 15 minutes of tallying, the board showed a tied vote — not enough to prevail. Then Andrew Jacobs, a Democrat from a pro-gun district to Indiana who had initially voted against the measure, approached the well and changed his vote.

After the slaughter of children in Connecticut, some traditionally pro-gun-rights members of Congress have signaled they, too, might be willing to budge, including Sen. Joe Manchin (D-W.Va.), Sen. Mark R. Warner (D-Va.) and Rep. John Yarmuth (D-Ky.).

One need look no further than the issue’s one time champions — among the most politically attuned leaders in recent American history — to measure just how far it had fallen off the radar.

Emanuel, who led the Democrats’ successful effort to retake the House in 2006, gained an appreciation for how skittish critical swing state members were on the gun issue and steered clear of the matter. When he joined the Obama White House as chief of staff, he blew a gasket, according to an account in the book “Kill or Capture,” when Attorney General Eric H. Holder Jr. suggested the administration would push to reinstate the assault-weapons ban. (Emanuel’s office said the mayor had a 20-year record of standing up to the National Rifle Association and fighting to get assault weapons off America’s streets.)

And Schumer, the great champion of the assault weapons ban in the House, become remarkably less vocal about it after winning election to the Senate and eventually leading his party to a majority in that chamber. (Schumer’s office insisted that the senator has picked his spots, whipping up votes against a bill that would have gutted laws criminalizing concealed weapons, fending off NRA-backed bills that would have made it easier for mentally ill veterans to get guns and authoring a gun-control measure that strengthened background checks after the 2007 Virginia Tech shooting.)

Yassky acknowledged that the NRA exercised real political muscle through its ability to trigger a flood of member phone calls to targeted congressmen who supported gun control measures. And, he adds, some elected officials did lose their seats in part because of the passage of the assault weapons ban, most notably Brooks, who sponsored the larger bill but opposed the ban. But he pointed out that plenty of members from pro-gun districts who supported the ban survived and that gun control was a popular issue for no less a political animal than Clinton to run ads in support of the issue in his 1996 reelection victory against Sen. Robert J. Dole. In 2000, Yassky helped write the gun-control portion of Al Gore’s platform, which called for a national gun license and registration framework — akin to driver’s license and registration.

After that, Yassky said, “the NRA myth took hold so much that people didn’t want to hear it.”

That Democratic bellwethers, Emanuel and Schumer, have again changed their tune may be a promising development for gun control advocates.

“It’s time that we as a city have an assault weapons ban,” Emanuel, the mayor of bullet-pocked Chicago said on Saturday. “It’s time that we as a state have an assault weapons ban, it’s time that we as a country have an assault weapons ban.”

The next morning, Schumer appeared on “Face the Nation” and called for a reinstatement of the assault weapons ban, a limit on the size of ammunition clips and stronger background checks to prevent “mentally unstable people to get guns.”

There is, of course, a central difference between 1994, when the assault weapons ban barely passed, and now. Republicans control the House, and they have been noticeably silent since the rampage in the elementary school.

Asked if the ban could be passed again, Jacobs, the decisive vote in the 1994 vote, who is now retired in Indiana, said “I kind of doubt it, in the present Congress.” The former combat veteran and police officer said that while “I was going to take some water” for his support of the ban, he didn’t let that factor into his decision making. “I used to say there are too many members of Congress who are scared of things that aren’t scary. I thought if you talked a little common sense, people would respond. They usually did in my case.” Jacobs said that the the ban’s restriction on high-volume magazines won his vote. “I made the argument at the time for the 10-round limitation, that when some maniac got on a playground, he would have to reload and children would have an opportunity to scurry to safety,” he said. “I think it’s rather ironic.”