Sanders has most to prove during Democrats' 2nd debate

The second debate of the Democratic campaign for president began Saturday nightwith a moment of silence for the victims of the attacks in Paris. 

Vermont Sen. Bernie Sanders faces the biggest test yet of his insurgent presidential campaign, when he faces off with Democratic front-runner Hillary Clinton in the party's second primary debate.

His goal is clear: Reset a contest that increasingly looks like little more than a march to the nomination for Clinton.

That effort will be complicated by fresh terrorist strikes that have captured the world's attention. Despite Sanders' focus on domestic issues, national security and foreign policy will play prominent roles in the debate, with the string of deadly attacks in Paris that killed more than 120 people front and center.

Vermont Sen. Bernie Sanders began with sharp language for the Islamic State, which has claimed responsibility for the attack in Paris.

He said, "Together, leading the world, this country will rid our planet of this barbarous organization."

But Sanders also pivoted from the attacks to the economic issues that are the focus of his campaign.

Front-runner and former Secretary of State Hillary Rodham Clinton kept to the attacks in her statement, saying "our prayers are with the people of France tonight."

She added: "But that is not enough. We need to have a resolve that will bring the world together to root out the kind of radical, Jihadist ideology that motivates organizations ISIS."

Clinton defended the Obama administration's initial approach to the rise of Islamic State, including her actions as secretary of state.

Clinton rejected the notion that she underestimated the militants, and she blames their rise on leaders in the Middle East and names former Iraqi Prime Minister Nouri al-Maliki.

Clinton said al-Maliki did not do enough to maintain stability in Iraq once the U.S. turned over control of the nation.

She added that she did advocate that the U.S. do more to "train and equip moderates" in Syria, which has since fallen into civil war.

Former Maryland Gov. Martin O'Malley touted his executive experience in his opening remarks, and says the U.S. needs "new thinking" and "new leadership" to respond to threats like those posed by the Islamic State.

Simply toppling dictators is not a suitable foreign policy for the 21st century, O'Malley said, referring to the U.S. invasion of Iraq in 2003.

O'Malley is attempting to draw a contrast with former Secretary of State Hillary Rodham Clinton on foreign policy during the second Democratic debate.

He said Syria, Libya and Afghanistan are "a mess" and that the United States isn't doing enough to build stable democracies after toppling dictators.

He added that the United States needs better "human intelligence" on the ground to understand what actors will step up to fill the void after dictators fall.

All three Democratic presidential candidates declined to use the term "radical Islam" at the party's second debate, a description used by many of their Republican rivals, who piled on Twitter to respond.

Former Florida Gov. Jeb Bush tweeted, "Yes, we are at war with radical Islamic terrorism."

Rick Santorum commented, "@HillaryClinton how can we defeat our enemy if we cannot identify who they are and what motivates them?"

Said Carly Fiorina on Twitter: "Hillary Clinton will not call this Islamic terrorism. I will."

Foreign relations is an area where Clinton, a former secretary of state, is in the strongest position to talk about the attacks and the U.S. effort to dismantle the Islamic State group. But her tenure is tied to that of President Barack Obama, who has struggled to contain the threat from armed groups in Syria and associated attacks across the globe.

Clinton's husband, former President Bill Clinton, accompanied her to Des Moines on Saturday but will not be in the hall for the debate, spokesman Angel Urena said.

A spate of good news for Clinton since the party's first debate a month ago has helped her rebuild a lead in the early voting states, an uptick that comes amid other signs the party is coalescing behind her.

An Associated Press survey of superdelegates published Friday found that half of the Democratic insiders are publicly backing Clinton.

Sanders may have inadvertently facilitated some of her progress in the first debate, when he seemed to dismiss the controversy over her use of a private email account and server by saying Americans are tired of hearing about her "damn emails."

Since then, he's given her no more passes.

Though careful never to mention Clinton by name, Sanders has drawn a series of contrasts with the former secretary of state on issues that include her backing of the war in Iraq, trade and the minimum wage.

The problem for Sanders is that Clinton agrees with him on some of the core domestic issues of his campaign, having shifted to the left in recent weeks to oppose construction of the Keystone XL pipeline and the Trans-Pacific Partnership trade deal.

"It's really tough for him," said Gina Glantz, manager of Bill Bradley's 2000 presidential campaign, which posed a primary challenge to then-Vice President Al Gore. "He's in a difficult position where his current arguments aren't enough to get beyond his core voter."

While Sanders aides bragged about their candidate's lax preparation for the last debate, they shuttled him to his campaign headquarters in Burlington, Vermont, for mock sessions before this match-up. Clinton, too, has kept her schedule relatively clear over the last several days, leaving plenty of time for rehearsals.

"They are absolutely prepared for the fact that Bernie's going to come out swinging," said Maria Cardona, a Democratic strategist who worked for Clinton's failed 2008 White House campaign. "The question is how it's going to happen."

Clinton supporters say their candidate will remain focused on laying out her vision for the future rather than striking back at Sanders. Her campaign has about $15.2 million in television advertising planned through mid-February, compared with a $3.2 million Sanders ad buy that ends next week, according to Kantar Media's CMAG advertising tracker.

The Service Employees International Union, an influential force in Democratic politics, is expected to issue their endorsement on Tuesday, according to people knowledgeable about the union's process. Clinton has been backed by more than 72 percent of members in all their internal polling, including the most recent survey conducted a few weeks ago.

Her team is hoping to notch another win after a series of strong moments since the first debate. Clinton has benefited from Vice President Joe Biden's decision to forgo a run and well-received testimony before a Republican-led congressional panel investigating the deadly 2012 attacks in Benghazi, Libya.

They're also trying not to alienate the Sanders backers whose support they'll need should Clinton win the nomination.

"As a front-runner your job is to do no harm," Cardona, the Democratic strategist, said. "She's going to want to be a comfortable home for the Bernie supporters toward the end of this process."

Sanders, too, may face tougher attacks. O'Malley, who has struggled to break 5 percent in national preference polls, has questioned Sanders' commitment to the Democratic Party and Obama, still a popular figure among many Democrats.

The Associated Press