text: Christie - 'Every place in America is a target'
  17:40 ET
  By the time the afternoon session of the Republican Jewish Coalition presidential forum was wrapping up, most of the participating candidates were all but certain as to the exact nature of the violence in San Bernardino.
  "I assure you it is an act of terror," said former Virginia Governor Jim Gilmore, later warning that this was just the beginning. "We have to be prepared because the world is breaking down."
  Carly Fiorina took aim at the likely Democratic nominee.
  "Hillary Clinton was tweeting about gun control while we learned that radical Islamic terrorists have been building pipe bombs," she said.
  And New Jersey Governor Chris Christie spent nearly his entire 30-minute speech talking about the implications of Wednesday's attacks.
  "For the first time since 9/11," he said, "we're going to have to confront the loss of American life on American soil to terrorist conduct."
  And he added some words of warning.
  "If a centre for the developmentally disabled in San Bernardino, California, can be a target for a terrorist attack, then every place in America is a target for a terrorist attack."
  The New Jersey governor is pinning what were once fading presidential hopes on national security. After the Paris attacks and the events on Wednesday, he feels the US public is giving him another look - and a recent poll of New Hampshire voters shows that he has gained some momentum, moving ahead of Ben Carson into fourth place.
  "The entire campaign changed a few weeks ago," he said. "We need to come to grips with the concept in America that we are in the midst of the next world war."
  He went on to attack fellow candidates Rand Paul by name and Ted Cruz by implication - both for voting in the Senate to support a rollback of National Security Agency surveillance operations that went into effect last weekend.
  "Every candidate who comes on this stage should be honest with you and tell you we need to do these things," he said. "And anyone who doesn't is putting American families at risk."
  13:30 ET
  According to Donald Trump, the violence in San Bernardino on Wednesday "probably was related" to "radical Islamic terrorism".
  During remarks at the Republican Jewish Coalition, the New York real-estate mogul wondered why President Barack Obama won't use those words.
  "There is something going on with him that we don't know about," he said.
  Several years ago, Mr Trump - before he was a presidential front-runner - made the rounds on the political talk show circuit as one of the leading voices of the "birther" movement - that bit of the conservative fringe that questioned the validity of Mr Obama's birth certificate and his American bona fides.
  Old habits, it seems, die hard.
  Rubio - 'We live in a different world'
  12:00ET
  "We certainly have learned some facts that are concerning and weigh on our minds,"  Marco Rubio said early in his speech before the Republican Jewish Coalition presidential forum.
  The Florida senator no doubt was referencing the possible Islamic ties of the assailants in the San Bernardino shooting - albeit in a much more oblique way than his fellow senator, Ted Cruz, did earlier Thursday morning.
  "We live in a very different world than the one I grew up in, the world that you grew up in and the world we had not long ago," Mr Rubio continued.
  While Mr Rubio's words were carefully, intentionally vague, Mr Cruz wasn't the only candidate to directly tie Wednesday's attacks to overseas terrorism.
  Inadequate gun-control laws are not to blame for the California shootings, South Carolina Senator Lindsey Graham told reporters after his speech.
  "It's about two people who have bought into an ideology that's just absolutely insane."
  Former New York Governor George Pataki said we don't know for sure whether the shootings in San Bernardino "involved terror or not", but it was a "horrible, horrible planned assault".
  What we do know, he continued, was that the bombings at the Boston Marathon, the shooting at the US Army base at Fort Hood and the foiled assault at an art exhibit in Garland, Texas - all of which have happened during Barack Obama's presidency - were "carried out by radical jihadists here in America".
  The US should not let First Amendment protections of free speech stand in the way of confronting this "warped view of jihad", Pataki continued, comparing a ban on inflammatory Islamic rhetoric to prohibitions on yelling "fire in a crowded theatre".
  "Radicalisation in America isn't protected speech," he said. "It is a crime, and we should stop it."
  10:43 ET
  Texas Senator Ted Cruz took the stage at the presidential forum hosted by the Republican Jewish Coalition and called for a moment of silence for the victims of the San Bernardino shootings.
  Then, while acknowledging "the details of what happened are still unclear", he said that he is "deeply concerned" that the events in California are "another manifestation of radical Islamic terrorism here at home".
  He said the San Bernardino shootings, along with the Paris attacks last month, "underscores that we are in a time of war".
  "Whether or not the current administration realises or wishes to acknowledge it," Mr Cruz continued. "Our enemies are at war with us. I believe this nation needs a wartime president to defend it."
  The Texas senator then pitched the audience of Republican Jewish activists and deep-pocketed conservative donors on why he's the man for the job.
  As he did in last month's Republican presidential debate, he chided President Barack Obama for not using the term "radical Islamic terrorism".
  A president, he said, must speak the truth. "When the president stands up and says the Islamic State isn't Islamic - that's just nutty," he said, calling Mr Obama an apologist for "radical Islamic terrorism".
  He said as president he would make sure the US does more to stand by its allies - Israel in particular - and defeat its enemies.
  "If you are voting for Hillary Clinton," he said, "you are voting for the Ayatollah Khamenei to have a nuclear device."
target: Republican presidential candidates speaking at a forum in Washington, DC, have responded to the mass shooting in California which left at least 14 dead.