It was a powerful moment on the White House lawn when thousands of guests, the loved ones of slain crime victims among them, crowded in as President Bill Clinton signed a sweeping crime bill that was six years in the making and included a hotly disputed ban on assault weapons.

“Today, at last, the waiting ends,” Clinton said on that day in 1994. “Today, the bickering stops, the era of excuses is over.”

Hardly.

Two decades and so many gun tragedies later, the political fallout from that long-gone assault weapons ban still casts a long shadow over Washington.

Gun-control advocates are scrambling to regroup after losing soundly to the National Rifle Association on their best opportunity in years to tighten gun laws. There’s no shortage of finger-pointing about what went wrong for them or theories about what to do next.

It was a grim-faced President Barack Obama who stood in the Rose Garden with a handful of family members of those slain at Newtown, Conn., after the Senate last week rejected background checks and other gun restrictions, including a new assault weapons ban.

“I see this as just round one,” the president said, raw emotion in his voice. “Sooner or later, we are going to get this right.”

But if the carnage at Newtown, the pleas of grieving family members and the persuasions of an engaged president weren’t enough to push gun restrictions through Congress, the road ahead is sure to be difficult for those advocating tighter controls.

In the immediate aftermath of the latest votes, with legislative strategy up in the air, gun control advocates are pinning their best hopes on two broad paths forward:

— Trying to counter the NRA’s impressive grass-roots network of nearly 5 million members by summoning more passion and energy from people who support restrictions such as an expansion of background checks for gun purchasers. Unless public demand for tougher gun laws “becomes a permanent fixture in politics to counterbalance the NRA, it’s only going to be by luck and happenstance that gun control actually wins,” said Dartmouth government professor Ron Shaiko, who has written extensively about the lobbying industry.

— Strengthening gun laws at the state level, where gun control advocates have had a number of significant victories in the months since Sandy Hook. “We’re seeing leadership that is coming from the states, and we’re going to be there to help that momentum and to make sure that momentum is felt here in this city, in Washington,” said Mark Kelly, who founded a gun control group with his wife, former Rep. Gabrielle Giffords, after she was shot by a gunman in Arizona two years ago.

The NRA is digging in for a long fight and claiming public support naturally trends its way.

“There’s a big misconception out there that gun rights are where they are because of the NRA,” said NRA spokesman Andrew Arulanandam. “The reality is that majority of Americans support gun rights and support self-defense laws.”

Polls paint a mixed picture.

In an Associated Press-GfK poll this month, 49 percent favored stricter gun laws, 10 percent wanted less-strict laws and 38 percent thought things should remain as they are. The poll found some slippage in support for stricter laws from earlier in the year.

On some measures, though, there is broad backing. Polls show 90 percent of those questioned support expanded background checks, for example.

Both sides agree there’s an intensity gap on gun politics. Opponents of gun restrictions have been far more passionate about the matter and far more apt to vote solely on the issue, than those on the other side.

“It’s where politics trumps policy,” said Richard Feldman, head of the Independent Firearms Owners Association, which supported the background check bill.

Obama entered his second term convinced of the need to marshal public support to push his agenda through Congress. After last week’s loss on guns, he said people were “going to have to sustain some passion about this.”

“You outnumber those who argued the other way,” he said. “But they’re better organized.”

It’s clear the fight, already expected at the federal level in 2014, will expand to include state elections.

“We’re prepared,” said Jeff Nass, president of WI-Force, a Wisconsin gun-rights group. “I think their loss nationally is going to bring it home to the states next year.”

On the other side, Jeri Bonavia of the Wisconsin Anti-Violence Effort said she expects groups such as Bloomberg’s Mayor’s Against Illegal Guns to spread into state races with advertising pressure that could diminish the NRA’s impact.

“If they do, it neutralizes the NRA’s pressure, and suddenly constituent voices matter more,” Bonavia said.