Council on Foreign Relations: on Homeland Security

Jeanne Shaheen: Support military spending, but don't undercut diplomacy

We know that women, when they're on peacekeeping forces, are better in dealing with conflict in lots of ways and not engaging in sexual violence and helping to address those issues. I think the more we can encourage women to be in those roles, the better, because it puts women in a place to make decisions that are important. It's one of the reasons I'm a big supporter of making sure that we opened up our military here in the United States to women at all levels.

Deval Patrick: Don't cast anti-terror policies on any one group

Patrick, who weathered criticism over his decision to shut down Boston's public services and bring in National Guard troops during the attacks, also argued that law enforcement must use their surveillance power prudently and that a mentality of "permanent lockdown" must be avoided to preserve American liberties.

Joe Walsh: Take seriously the dangers of Islamic terrorism

Walsh previously accused the Barack Obama administration of skewing intelligence to downplay the threat posed by terrorist groups such as al-Qaeda and the self-proclaimed Islamic State.

He has opposed readmitting into the United States former citizens who renounced their citizenship to join terrorist groups.

Mike Bloomberg: Expanded surveillance kept NYC safe from terrorists

His administration's approach to counterterrorism was controversial, with his increased surveillance measures drawing criticism for relying on racial and religious profiling and violating civil liberties. In the wake of the 2013 Boston Marathon bombings, he argued that "our laws and our interpretation of the Constitution, I think, have to change" to accommodate increased surveillance and other restrictions necessary to ensure public safety.

He argues that technology companies should be required to cooperate with government investigations by sharing customer data.

Mike Bloomberg: Argued against increasing military spending

He advocates for a new congressional authorization for overseas military operations, many of which currently rely on two-decade-old legislation, to put them "on sound legal footing."

He points to his mayoral record on veterans' issues. His administration's programs included job placement and career assistance services, a veteran-run job center, and a joint program with the Department of Veterans Affairs to combat veteran homelessness in New York.

Tom Steyer: Refocus and reduce U.S. military spending

Pete Buttigieg: Bring troops home from Afghanistan except for Special Ops