US presidential candidate Hillary Clinton will take on rival Bernie Sanders at the third Democratic debate, amid accusations that a data breach was carried out by his camp.
The Democratic National Committee (DNC) temporarily suspended the Sanders campaign's access to a key voter database after at least one of its staffers took advantage of a computer glitch to peek at Clinton voter data.
The debate, which also includes former Maryland governor Martin O'Malley -- who polls far behind his two rivals -- will be held at 8:00 pm local time (0100 GMT today) in Manchester, New Hampshire.
Hosted by television network ABC, the occasion marks the first debate since the deadly attacks on San Bernardino, California, which killed 14 people.
National security and foreign affairs are expected to dominate the evening -- both of which are weak points for Sanders, who is more comfortable talking about economic inequality and financial abuse, topics that are the cornerstones of his campaign.
Before the data breach the week had gone well for Sanders, who broke a record by reaching two million mostly small donations. No Democratic or Republican presidential candidate has ever received so many contributions at this stage in the race.
Clinton, who has raised much more money than Sanders, has depended on large checks from big donors.
Sanders on Thursday also received his biggest labor endorsement to date from the 700,000 member Communications Workers of America (CWA).
But with security taking center stage at the debate, Clinton benefits from the four years she spent as US secretary of state (2009-2013).
Clinton reassured voters in a speech at Minneapolis on Tuesday that she would destroy the Islamic State group but not launch a ground war in the Middle East. She also highlighted the differences with her Republican foes, notably front runner Donald Trump and his incendiary statements.
Sanders, however, is likely remind viewers of Clinton's 2002 vote when she was New York senator authorizing president George W. Bush's use of military force in Iraq.
In national polls among Democrats, Sanders has 31 percent support, a number that has remained constant since early November. Clinton's support in the mid-50s.
Disagreeing with his rival, Trump said, "We need a Supreme
Court that in my opinion is going to uphold the Second Amendment, and all amendments, but the Second Amendment, which is under absolute siege."
"I believe if my opponent should win this race, which I truly don't think will happen, we will have a Second Amendment which will be a very, very small replica of what it is right now. But I feel that it's absolutely important that we uphold, because of the fact that it is under such trauma," he said, adding he has already shortlisted and made public names of 20 such nominations.
Arguing that America should not have judges appointed who decide what they want to hear Trump said, "it's all about the Constitution of and so important, the Constitution the way it was meant to be. And those are the people that I will appoint."
Clinton responded saying that she supports the Second Amendment.
"I understand and respect the tradition of gun ownership. But I also believe that there can be and must be reasonable regulation. Because I support the Second Amendment, doesn't mean that I want people who shouldn't have guns to be able to threaten you, kill you or members of your family," she said.
The United States need comprehensive background checks, to close the online loophole, close the gun show loophole, she added.
"There's other matters that I think are sensible that are the kind of reforms that would make a difference that are not in any way conflicting with the Second Amendment," she argued.
Referring to the National Rifle Association (NRA) endorsing Trump, Clinton said they are running millions of dollars of advertisements against her.
Citing examples of cities like Chicago, Trump said tough gun control laws does not help.
"In Chicago, which has the toughest gun laws in the United States, probably you could say by far, they have more gun violence than any other city. So we have the toughest laws, and you have tremendous gun violence.
"I am a very strong supporter of the Second Amendment. I'm very proud to have the endorsement of the NRA. And it's the earliest endorsement they've ever given to anybody who ran for president," he said.
