Bernie Sanders, a favorite of grass-roots liberals despite his mixed record on gun control, joined his Senate colleagues Thursday in calling for a crackdown on firearms a day after the mass shooting in San Bernardino.

Standing alongside California’s two Democratic senators, Barbara Boxer and Dianne Feinstein, at a Capitol Hill news conference, Sanders said the steps he supports include expanded background checks and efforts to keep firearms out of the hands of people who commit domestic violence.

“Let me paraphrase what President Obama said recently. And what he said is this is not an easy problem to solve. But just because it is not an easy problem to solve does not mean that we should not do everything that we can,” the Vermont senator said. “Now, the bad news is that this nation is divided over gun legislation.”

Sanders’ comments were similar to statements he has made throughout his bid for the Democratic presidential nomination, where he faces a two rivals, Hillary Clinton and Martin O’Malley, with a history of backing tougher gun controls.

In 2005, for instance, Sanders supported legislation protecting gun manufacturers and sellers from lawsuits seeking to hold them liable when firearms end up in criminal hands.

“That was a terrible mistake," Clinton said in last month’s Democratic debate. “It basically gave the gun lobby even more power to intimidate legislators, not just in Washington but across the country.”

In response, Sanders said there were elements of the bill he supported but repeatedly demurred when asked if his vote had been a mistake.

O’Malley suggested Thursday that the shootings at a San Bernardino center for the developmentally disabled could be a lead to change in the fractious gun control debate.

"'We’ve now had more mass shootings than we’ve had days in this year, and perhaps this is the incident that tips the balance and we finally do this,” O’Malley said in an interview on the Fusion television network.

Efforts to pass tougher federal gun laws have stalled because of deep partisan polarization, even after repeated mass shootings, including incidents in 2012 at an Aurora, Colo., movie theater and at Sandy Hook Elementary School in Newtown, Conn.

In general, Democrats have called for stiffer gun laws while Republicans have said a crackdown on firearms would infringe on the 2nd Amendment rights of gun owners.

For her part, Clinton said Thursday that tougher gun control is needed.

"We need to take action now," she said in a note to supporters on Twitter.

Jeb Bush, speaking before the Republican Jewish Coalition forum on Thursday, made some eyebrow-raising comments that fired up social media.

A nationwide hunger strike at immigrant detention centers has Vermont Sen. Bernie Sanders lauding the effort to protest conditions at the facilities, which have been described as inhumane.

Since October, several dozen immigrants in centers from California to Texas have been refusing to eat over what they describe as prolonged detention, with many waiting months or years while their cases play out in immigration courts.

Sanders is committed to “humane and secure immigration policy, which includes ensuring that people escaping violence and severe poverty are given a fair opportunity to present their claims,” Arturo Carmona, Sanders’ Latino outreach director, said in a statement Thursday.

“These aspiring Americans should not be criminalized, subjected to dehumanizing solitary confinement or indefinitely detained,” Carmona said.

Most of those refusing meals are asylum-seekers from South Asia or Africa who have been held for months or years. A majority are Muslim.

On Thursday, Fahd Ahmed, an immigrant rights advocate who helped coordinate the strikes, planned to rally outside Hillary Clinton’s New York City campaign headquarters to draw attention the effort and try to win support for it. Clinton’s campaign did not immediately return a request for comment.

Questions about who qualifies for asylum and what that process should look like have been widely debated in recent years, as millions of Syrians have fled their country’s five-year-old civil war and tens of thousands of minors fleeing violence in Central America have shown up at the southern U.S. border.

And the debate has made its way into the 2016 presidential campaign.

Many Republican presidential hopefuls, including front-runners Donald Trump and Ben Carson, have said they do not support the Obama administration’s plan to offer shelter in the U.S. to at least 10,000 Syrian refugees this fiscal year.

"We have no idea who these people are; we are the worst when it comes to paperwork," Trump told reporters recently, citing what he said were difficulties in running background checks on the refugees. "This could be one of the great Trojan horses."

Candidates for the Democratic nomination, including, Clinton, Sanders and former Maryland Gov. Martin O’Malley have backed the effort to allow refugees to enter the U.S.

Staff writer Kate Linthicum contributed to this report.

If Republican presidential front-runner Donald Trump shows up at the next CNN debate, it will be for free.

CNN President Jeff Zucker said Thursday during a breakfast conversation at the Paley Center for Media that his network does not pay candidates for showing up at debates. That rule holds for Trump, who has been a ratings magnet for the Republican primary debates in the 2016 race for the White House.

Trump said Monday at a campaign stop in Georgia that his presence at the debates has turned them into revenue windfalls for the cable news networks that carry them and that he wanted $5 million for CNN's next debate scheduled for Dec. 15 in Las Vegas. He said he would donate the payment to charity.

Americans "need to come to grips with the idea that we are in the midst of the next world war," New Jersey Gov. Chris Christie said Thursday.

Some candidates at Thursday's candidate forum sponsored by the Republican Jewish Coalition in Washington avoided any mention of the shootings the day before in San Bernardino. Others mentioned them only in passing. Christie made the rampage a focal point of his speech.

“From the time I began to watch the events unfold last night, I [was] convinced that it was a terrorist attack,” said Christie.

“The president continues to wring his hands and say ‘we’ll see.’…But those folks dressed in tactical gear with semi-automatic weapons came there to do something.”

Christie warned that the shooting should be a wake-up call for stepped up national defense and intelligence. He made no mention of gun control laws, which have been the focus of the Democratic response to the massacre.

“If a center for the developmentally disabled in San Bernardino, Calif., can be a target for a terrorist attack, then every place in America is a target for a terrorist attack,” Christie said.

He tied the attacks to those of Sept. 11, 2001, drawing on his personal experience as the U.S. attorney in New Jersey in the aftermath of that attack and as the neighbor of people who perished in the World Trade Center.

“These acts of terrorism are not theoretical to me,” he said. “It’s not something I've been briefed about in the basement of the Capitol, not something I saw on TV.”

“What I am worried about now as a nation is that we are forgetting,” he said. “As a nation we have become complacent and soft and unwilling to do the difficult things that need to be done.”

While the facts surrounding the San Bernardino incident remain murky, he added, what is clear is that law enforcement and intelligence agencies were blindsided, just as they were in Paris before the deadly shootings there last month.

Christie blamed weak leadership.

“We need to do these things,” Christie said of his call for more aggressive law enforcement and a hawkish foreign policy. “If we don’t do them, then we are putting you and your family at risk.”

Hillary Clinton expressed sorrow Thursday over the “terrible” shooting attacks in San Bernardino and called for renewed international cooperation to combat extremism, though she cautioned that the motive behind the rampage was still unknown.

“I want people to feel safe. If you go to the store, or you go to work, you go to the movies, you go to church, you take your kid to school — you should be safe,” Clinton said after a campaign-trail tour of a pin factory in Nashua, N.H.

Acknowledging that President Obama has said terrorism could not be ruled out as a motive for the massacre that killed 14, Clinton reflected on the prowess that terrorist networks like Islamic State have demonstrated in spreading their views online.

“We have to fight them in the air, we have to fight the on the ground and we have to fight them in cyberspace,” she said. “They’re so good on the Internet. They’re good at recruiting; they’re good at propaganda. They are good at even inciting acts of violence.”

Clinton said it was critical to lead the world in working to prevent “the kind of attacks we’ve been seeing,” she told reporters, though it was not immediately clear whether she was referring still to the San Bernardino shooting.

Amid the caustic political rhetoric over gun control, as well as the U.S. strategy to combat Islamic State, Clinton bemoaned negativity at a time she said we should “start acting like one nation again.”

“We’ve got too many disagreements, too much division, and people are being kind of negative. And there’s nothing we can’t do if we get our focus together, if we start working with people again,” she said. “We’re going to have differences. But there’s got to be a way to end some of the hot rhetoric and the negative attitudes that people are spewing forth.”

President Obama’s refusal to use the terms “radical Islamic terrorism” indicates that “there is something going on with him that we don’t know about,” Donald Trump said Thursday.

The comment, delivered at a forum of Republican Jewish fundraisers and activists in Washington, was made in response to the rampage in San Bernardino on Wednesday. It carried echoes of Trump’s history of questioning Obama’s birthplace and his airing of false claims that Obama is Muslim.

The attack on Wednesday “probably was related” to Islamic terrorism, Trump said, while leaving some room for doubt.

“It always happens,” he said was his first reaction to the attacks, suggesting he viewed the massacre as a random act of violence and not a planned terrorist attack.

“When I heard about it, I figured probably not. But it turns out, probably related.

“Radical Islamic terrorism,” he added. “We have a president who refuses to use the term. Refuses to say it. There is something going on with him that we don’t know about.”

Trump’s remarks to the Republican Jewish Coalition were light on policy, with several remarks that appeared to be efforts to connect with the audience, some of which caused raised eyebrows.

Trump noted that one of his daughters is Jewish. Other comments touched on long-standing Jewish stereotypes.

“I’m a negotiator, like you folks,” he said at one point.

“You’re not going to support me because I don’t want your money,” he said at another.

Trump drew mostly laughs. But there were boos when he declined to commit to recognizing Jerusalem as Israel’s capital. Successive administrations of both parties have declined to take that step, fearing it would be provocative in the Arab world. But many Jewish conservatives, who were heavily represented in the audience, see it as a priority.

Trump was also vague when asked which Arab leaders he could work with, mentioning the King of Jordan without using his name and then veering into other topics, including his relationships with Democrats and others he has met during his career in real estate.

His biggest policy message was a critique of Obama – “the worst thing that’s ever happened to Israel” – and the deal his administration struck with Iran designed to stop its nuclear weapons program.

"It is possible" that the deadly shooting in San Bernardino "was terrorist-related, but we don't know," President Obama said Thursday morning.

Speaking from the Oval Office after a briefing from FBI Director James Comey, Obama emphasized the need to "get the facts" before making a judgment about the case.

It is "possible this was workplace related," he said.

"At this stage, we do not yet know why this terrible event occurred," he said.

But, he added, "right now, it's just too easy" for people who are determined to kill others to "get access to weapons."

“We live in a very different world than the one I grew up in,” Sen. Marco Rubio said Thursday, offering his first reaction to Wednesday’s deadly shooting rampage in San Bernardino.

Rubio opened his speech to a forum sponsored by the Republican Jewish Coalition by offering “our thoughts and prayers” to the community. He quickly segued into prepared remarks focusing on how dangerous the world has become and his charge that the Democrats have failed to stand with Israel.

“We don’t know all the facts yet,” Rubio said of the San Bernardino shootings. “But we have certainly learned some facts that are concerning and weigh on our minds.”

Threats facing our country and Israel have grown in recent months,” he said.

Each of the Republican candidates is scheduled to speak at the forum sponsored by the coalition, which is led by Las Vegas casino magnate Sheldon Adelson.

Even as the details of Wednesday’s massacre in San Bernardino were “still unclear,” the “horrific murder underscores that we are at a time of war, whether or not the current administration realizes it,” Texas Sen. Ted Cruz said Thursday.

“We need a president who will call the enemy by its name: radical Islamic terrorism,” he said. “There’s a power of speaking the truth.”

Cruz, who has been rising in Republican polls lately, spoke in Washington at a forum of the Republican Jewish Coalition, a group of powerful GOP fundraisers led by casino magnate Sheldon Adelson.

Leaders of the forum noted that they were the only group able to attract all of the Republican presidential candidates to a single event, other than official debates. The coalition puts a premium on conservative policy in the Middle East, with particular focus on Israel.

Cruz won a standing ovation as he accused the Obama administration of denying the core causes of terrorism.

“We have a president who, at times, operates as an apologist for radical Islamic terrorism,” he said.

"At this point, the details of what happened in San Bernardino are still unclear," he said. "But our prayers are with the families of those who were murdered and those who were shot. And all of us are deeply concerned that this is yet another manifestation of terrorism, radical Islamic terrorism here at home."

"Coming on the wake of a terror attack in Paris, this horrific murder underscores that we are in a time of war," he said.

In the wake of the massacre that killed 14 in San Bernardino on Wednesday, Republican front-runner Donald Trump shared his condolences. But within hours, his Twitter stream tinged his sympathy with the uglier side of politics.

At a rally Wednesday night in Manassas, Va., Trump praised law enforcement, saying that mass shootings were the time to appreciate police and others working in public safety.

"They don't get enough credit," he said. "They should get it, and you're always going to have some bad apples."

But on Thursday morning, Trump appeared to tie the shooting and the ongoing debate over guns, policing and safety to perhaps his favorite topic - himself. Trump retweeted a series of tweets suggesting his poll numbers climb each time a mass shooting happens.

The retweets drew ire from Trump’s legion of critics.

For his part, retired neurosurgeon Ben Carson, who has also led the crowded GOP field in several polls in recent weeks, labeled the rampage in San Bernardino a hate crime and lamented the spate of recent shootings in the U.S. But he noted that violence exists elsewhere in the world, mentioning the Islamic State extremists who control parts of Iraq and Syria.

"Just hatred and evil," Carson said of both the mass shootings and Islamic State. "And we need to be able to combat these things because otherwise we will melt into despair. And that's not who we are. This is America."

Former Florida Gov. Jeb Bush told Iowa Public Television that both Trump and Carson are in general campaigning for attention and lack the serious mentality to lead the country. The interview was taped in the morning before the attack in San Bernardino.

Trump’s suggestion after the Paris attacks to implement a database to track all Muslims in the U.S. was inappropriate, Bush added.

"[Trump] is not going to apologize for anything; he's not a serious person. It's hard to imagine him being president of the United States. If he gets upset, is he going to start disparaging our allies?" Bush said, according to an excerpt from the interview, which is to air in full this weekend. "This lack of seriousness is a serious problem for our country. If a guy, capable as he is as a politician, became president, has no clue what he's doing, that's a dangerous thing."

Bush himself expressed condolences later Wednesday for what happened in San Bernardino and offered the community his prayers.

Bush also said that Carson’s response to Islamic State and calling Syrian refugees “rabid dogs” reflects an immature outlook. Carson, who traveled to Jordan over the Thanksgiving holiday in an effort to bolster his foreign policy credentials, has insisted that the media misinterpreted what he was saying.

Is the way to Iowans’ hearts through their caucus?

Martin O’Malley apparently hopes so.

The former Maryland governor has been marginalized in what essentially amounts to a two-person race for the Democratic presidential nomination, trailing far behind Hillary Clinton as well as her main rival, Vermont Sen. Bernie Sanders.

So O’Malley this week seized upon a private comment Clinton made in 2012 about political caucuses, referring to the precinct-level gathering of campaign activists and partisan faithful as “creatures of the parties’ extremes.”

Which has a distinct ring of truth, however indelicate the phrasing, as it does take a certain out-of-the-ordinary willingness to participate given the extremes — of winter weather and prolonged procedure — it takes for Iowa caucus-goers to register their presidential favorites.

Rushing the battlements (or at least taking to the radio airwaves), O’Malley immediately declared his umbrage on behalf of the Hawkeye State and its civic-minded masses.