"This is not something I can do by myself," Obama said in an emotional White House appearance Thursday evening after nine people died in a shooting at a community college in Oregon.
"It will require that the American people, individually, whether you are a Democrat or a Republican or an Independent, when you decide to vote for somebody, are making a determination as to whether this cause of continuing death for innocent people should be a relevant factor in your decision," Obama said.
His remarks Thursday and again during a news conference Friday
when he vowed to keep talking about the issue were not just a reflection of frustration, but also of personal failure.
Since his push to enact a ban on assault weapons and wider background checks for gun owners collapsed on Capitol Hill in 2013, gun control has slipped down the list of White House priorities, below a legacy-building Iran deal, an opening with Cuba and reform of the immigration system.
Obama, by his own admission, has now become little more than a grim scorekeeper after mass gun massacres -- a role that on Thursday night he bitterly complained has become routine. He seems destined to turn off the lights at the White House in 16 months without substantial change on gun legislation. In office, the guns issue has been much more nettlesome than it appeared during the 2008 presidential campaign, when Obama said it should be possible to get illegal guns off the streets and prevent them from falling into the hands of the mentally ill.
"What we have to do is get beyond the politics of this issue and figure out what, in fact, is working," Obama said at a presidential primary debate in Philadelphia.
Seven years on, Obama is still struggling to get past those politics -- but some gun-rights advocates believe he has tried his best.
"The general idea that the president hasn't done enough -- I just don't see that at all -- he was physically sick yesterday," said Ladd Everitt, communications director for the Coalition to Stop Gun Violence.
"He can't run Congress, he can't cast congressional votes."
Though the White House push to overhaul gun legislation failed in 2013, Obama did order 23 executive actions designed to reduce violence with firearms, though he admitted congressional action would be much more meaningful.
The White House says it has made progress on all the measures, including those requiring federal agencies to share information on the background check system, to trace guns recovered in criminal investigations and to review standards for gun locks and safes.
But those measures are small ball in a nation swamped by hundreds of millions of guns
and where the politics of the issue are shaped by the political muscle of the National Rifle Association.
The White House has failed to find traction on a middle ground that would allow meaningful reform to thrive while protecting the constitutional right to bear arms -- a compromise that would enjoy broad public support and still represent a practical way of regulating the firearms industry.
And Obama seems to know it, allowing a note of self recrimination to creep into his voice on Thursday night.
"This is a political choice that we make to allow this to happen every few months in America. We collectively are answerable to those families who lose their loved ones because of our inaction."
In a sense, Obama initially made his own political choice not to pursue gun reform -- at the moment when his political influence was at its apex, when Democrats controlled both the House and the Senate after he took office in 2009.
With a financial crisis raging and with other priorities, including health care reform, sucking up his political capital, there was no room for firearms reform.
The consequence of that choice became clear in 2013, when even a watered-down bill on background checks fell victim to a Senate filibuster by four votes -- even with shock still fresh from the gunning down of 6-year-old schoolkids in their classes in Newtown, Connecticut.
Eighty-five to 90% of Americans tell pollsters they favor tightening background checks to stop criminals or mentally ill people from getting weapons. Despite those numbers, there is little political momentum for change.
The chances of meaningful gun control reform are slim to none until the political mix changes in Washington -- and that could take years, since Republicans who rely on a base of voters resistant to such measures control the House of Representatives and the Senate.
Republican presidential candidates reacted to Thursday's shooting by uniformly resisting new gun control measures. Sen. Marco Rubio, for instance, said: "There is just no evidence that these gun laws would prevent these shootings."
Still, some gun-control advocates say Obama could do more than talk.
"We believe that on a few very specific fronts they can do more to crack down on bad-apple gun dealers, the very small percentage of gun dealers who sell almost every crime gun in the U.S.," said Dan Gross, president of the Brady campaign.
"The ATF has the power to crack down on them and pull their licenses if they are responsible for business practices that wind up causing gun crime and gun violence."
The White House could also lead a national conversation on the public health and safety risks associated with gun ownership, said Gross. After all, the administration does have a campaign on healthy eating, so why not guns?
"In our opinion, they haven't done all that they can do to really lead that conversation that could result in safer homes and saving a lot of lives," Gross said.
Looking outside Washington could also work.
Increasingly, gun-reform advocates are turning away from the impasse at the federal level to the states -- eight of which have now introduced expanded criminal background checks on private gun sales.
Nevada has scheduled a ballot initiative in November 2016 which would require background checks and close loopholes on online sales and at gun shows. Maine is also expected to follow suit.
Such developments hint at the reality that political change is often the work of generations rather than years -- and can span a number of presidencies. For now, polling shows little consensus on the way forward.
In a Pew Research poll in July, 71% of Republicans said protecting the constitutional right to bear arms was more important than gun control. Among Democrats, the figures were almost exactly reversed.
While such data explain Republican caution, it may offer an opportunity for Democrats, and one -- Hillary Clinton -- has noticed.
"I think that what we need is a national movement," Clinton said Thursday.
"We're going to go at this from the top down, namely go back to the Congress, go back to try and put together a sensible, bipartisan position that was supported before in the Senate to get to universal background checks.
"But we're also going to go from the bottom up. I'm going to make this a voting issue, because what the NRA does in their single-minded, absolutist theology about the Second Amendment being sacrosanct."
Gun-control advocates are also taking heart from other sweeping political transformations -- including the stunning shift of opinion on same-sex marriage -- which started in the states and left federal politicians racing to keep up.
"I think, I very much believe now, that on the gun issue we are going to have our Confederate flag or our gay-marriage moment, when there is a cultural break," Everitt said.
But for all the optimism, the NRA has a 30-year head start in perfecting how to frame the gun argument -- in which every modest gun-regulation effort is spun as an attempt by the federal government to snatch away the guns of law-abiding Americans.
"The politics has to change," Obama said, still fuming, in the aftermath of the Oregon shooting when he met reporters on Friday afternoon.
"People who are troubled by this have to be as intense and as organized and as adamant about this issue as folks on the other side."