WASHINGTON _ Sen. Dianne Feinstein's long pursuit of stricter gun laws began more than three decades ago on a day of bullets and bloodshed in San Francisco, when she was the president of the city's Board of Supervisors.
On Nov. 27, 1978, former supervisor Dan White walked into City Hall with a grudge and a .38 revolver. He fatally shot Mayor George Moscone, walked past Feinstein's office and then turned his weapon on Supervisor Harvey Milk, one of the country's first openly gay elected officials and a rising political star.
Feinstein, who'd run for mayor twice and lost and who wasn't planning to seek re-election, had to announce the deaths of her colleagues to a stunned city that now looked to her to lead.
The shootings recast her political career, becoming its consequential moment and one that's forever defined her in the public sphere. They also infused Feinstein with an unwavering advocacy for an issue that can come only when you've reached into the bloody wound of a colleague and frantically _ but fruitlessly _ searched for a pulse.
Through two terms as mayor of San Francisco, an unsuccessful run for governor and more than two decades in the U.S. Senate, no issue has motivated Feinstein more than stopping gun violence, according to current and former colleagues and members of her staff.
She led the campaign to pass the original assault weapons ban in 1994, which expired in 2004 after it couldn't attract enough support for renewal. The massacre of 20 elementary school children in Newtown, Conn., in December, however, so shocked and revolted the nation that the political climate has become as favorable as it's been in years to try to enact tighter rules on gun sales.
A four-term Democrat, the 79-year-old Feinstein is playing a leading role once again in the effort to control who may acquire guns, which guns they may buy and how much firepower is too much.
She probably won't get all she wants; her opponents, led by the National Rifle Association, wield considerable influence on Capitol Hill.
The Senate Judiciary Committee is considering her legislation, the Assault Weapons Ban of 2013. It must pass the committee before the full Senate has a chance to vote on it. Passage in either forum is far from guaranteed.
When she became mayor, the .38 revolver that White used to kill Milk and Moscone was a standard-issue weapon in police departments. When she became a senator, the police had increased their arsenal to match what they were up against on the street.
"I've watched police departments get outgunned," she told the committee last week.
Her legislation would ban assault weapons, restrict sales of ammunition clips with more than 10 bullets and expand background checks to gun shows and private sales.
"These weapons, which are really designed to kill as many people in close combat as big clips will allow, become attractive to grievance killers, gangs and people who are not all there mentally," Feinstein said in an interview.
Her opponents, particularly NRA Executive Vice President Wayne LaPierre, have accused her of a decades-old agenda against guns. During a hearing last month on Feinstein's bill, the NRA used Twitter to ridicule her knowledge of firearms and question the credibility of the law enforcement witnesses called to testify in support of the measure's restrictions.
"In the hour that (she) has been holding her hearing aimed at banning AR-15s," read one tweet, referring to a type of weapon Feinstein would like to see off the streets, "Americans have bought 150 more." Then it urged opponents to stop her.
Feinstein has said that her repeated attempts to ban assault weapons have nothing to do with preventing people from defending themselves.
"She's not afraid of guns," said Susan Kennedy, a political consultant and former Feinstein aide.
After a militant anti-capitalist group called the New World Liberation Front tried to bomb her house in the 1970s, she got trained to use a gun.
"I know the urge to arm yourself, because that's what I did," she told Senate colleagues in 1995. "I made the determination that if somebody was going to try to take me out, I was going to take them with me."
To Feinstein, the battle is about keeping what she considers weapons of war out of the hands of those who intend to massacre innocent people. And it's not just her personal experience that impels her to wage it.
Before the December shootings at the Sandy Hook Elementary School in Newtown, there was the Cleveland Elementary School shooting in Stockton, Calif., in January 1989. A 26-year-old man opened fire on a group of children with an AK-47 rifle, killing five and wounding more than 30 before taking his own life.
Before the movie theater shooting last July in Aurora, Colo., which left 12 dead and 58 others wounded, there was the office tower shooting at 101 California St. in San Francisco in July 1993. A gunman with a grudge against a law firm shot and killed eight people with an automatic weapon before killing himself.
As time has passed, these tragedies have faded from public memory. But Feinstein has not forgotten.
"This is something I'm deeply passionate about, and I believe it saves lives," she said. "I don't intend to stop."
Feinstein is married to investment banker and philanthropist Richard Blum. Their estimated net worth, between $46 million and $108 million, makes her one of the Senate's 10 wealthiest members.
Those who know her said she could be done with the frustrations and political intransigence of Washington and lead a major corporation or nonprofit, or simply enjoy a nice life in California, where she and Blum share a home in the affluent Pacific Heights section of San Francisco.
"There are no limits on what she could do and be successful at," said U.S. Rep. Mike Thompson, a Democrat from nearby Napa County who's a hunter and a leading supporter of an assault weapons ban. "She's here because of a passion and a commitment."
Feinstein is a veteran lawmaker who knows how to work behind the scenes and across the aisle, which is how much of the real business of Capitol Hill gets done.
"She's developed a chain of colleagues she can call on," Kennedy said. "She knows very well how to use her position on other committees."
Feinstein is an influential member. She ranks 14th in Senate seniority. Besides her seat on the Judiciary Committee, she serves on the powerful Appropriations Committee and chairs the Intelligence Committee.
Her political roots took hold at a time before bitter partisanship began to color every debate, and even relationships on Capitol Hill.
One of her closest friends has been Kay Bailey Hutchison, a Texas Republican who left the Senate in January. And Feinstein has warm relations with many more lawmakers, in an era fraught with political polarization.
Sen. Jeff Sessions, R-Ala., a staunch conservative who serves alongside the liberal-leaning Feinstein on the Judiciary Committee, said that while they disagreed on many issues, including the assault weapons ban, he admired her ability to forge compromise.
"I'd say on the 16 years I've been on it, she's been one of the more effective Democratic senators at reaching across the aisle on key issues," he said. "She battles for what she believes in, but she's also very able at finding common ground and solving problems."
In the latest fight over assault weapons, however, common ground appears to have eluded her. Nearly three months after the Newtown massacre, every co-sponsor of Feinstein's bill is a Democrat.
"I thank those who are with me," Feinstein said last week as the committee began voting on amendments to her bill. "I don't know that I can convince those who are not, but I'm going to keep trying."
It will be a tough vote for some lawmakers, including several Democrats who face re-election next year.
Feinstein said there was "no magic formula" to collecting enough votes to pass her bill. But political handicappers give the assault weapons ban little chance in either chamber, and any restriction on the size of ammunition clips also might be a tough sell. Efforts to strengthen background checks may have a better chance.
Friends and colleagues said Feinstein would push as hard as she could for every measure she'd proposed, but that ultimately she'd take something over nothing.
"At the end of the day, that's what every elected official has to do," said former California Gov. Gray Davis, whom Feinstein defeated in the 1992 Democratic Senate primary. "But she wouldn't take on this fight if she didn't think she could win."
Lawmakers were hardly unified on the idea of banning assault weapons 20 years ago, when the first measure passed.
"Many people thought she was on a fool's errand," Davis said.
The NRA and other critics contend that the ban and other measures would do little to stop criminals from buying guns and instead would punish law-abiding gun owners. But Feinstein said she wondered whether if the original assault weapons ban hadn't expired, it might have continued to dry up the supply and maybe even prevented Newtown and other tragedies.
"I've seen what's happening in our society as a product of these," she said. "It's just too much. We can put an end to it, and we should."
She said multiple polls found that a majority of Americans supported the assault weapons ban, and that many gun owners disagreed with the NRA's position. Rather than forcing legislation the public doesn't want, she's responding to the public will, she said.
But even with the Aurora and Newtown shootings fresh in the nation's consciousness, the political obstacles might mount as more time goes by.
"This is one of the biggest battles she will have in her career," said Kennedy, who's also worked for Davis and for Republican former California Gov. Arnold Schwarzenegger.
Feinstein's efforts have the support of law enforcement agencies, medical associations, religious organizations and mayors across the country. New York Mayor Michael Bloomberg, a leading gun-control advocate, is among her allies, as are Democratic former Arizona U.S. Rep. Gabrielle Giffords, the victim of a shooting rampage, and her husband, retired astronaut Mark Kelly, both longtime gun owners. President Barack Obama also supports her bill.
"The NRA is not going to slow her down," Davis said.
She's beaten the odds before. In April 1983, Feinstein faced a recall election in her first term as mayor over her support for a handgun ban. She won the recall with 82 percent of the vote and crushed her opponents later that year to win re-election.
She lost the race for California governor in 1990 to Republican Pete Wilson, but she came back two years later and won her Senate seat.
"She's absolutely tenacious," Thompson said. "And I don't think she's ever satisfied."