How Long Each Candidate Spoke Economy Health care Immigration Gun control Climate change Foreign policy How Long Each Candidate Spoke Each bar segment represents the length of a candidate’s response to a question.

Senator Cory Booker of New Jersey and Beto O’Rourke, a former congressman from Texas, spoke the most during the first Democratic presidential debate. Ten candidates participated on Wednesday, and 10 more will be part of a second debate on Thursday.

Here are some key questions the candidates were asked, where they found common ground and where they disagreed.

How Would You Address Gun Violence?

The candidates mostly agreed on the need to tighten the country’s gun laws, though some highlighted different priorities.

We need to treat it like a serious research problem which we have not done. We need to start dealing with the trauma that our kids have. We need trauma-based care in every school. If we’re going to stop these shootings we have to get these guns off the streets. We have to have a very different relationship between our police and our community. If you need a license to drive a car, you should need a license to buy and own a firearm.

Should Illegal Entry Be a Crime?

The two Texans, Julián Castro and Mr. O’Rourke, disagreed over whether to maintain a section of the law that criminalizes illegal entry into the United States. Mr. Castro’s plan would downgrade illegal entry to a civil offense.

Mr. Booker and Representative Tim Ryan of Ohio agreed with Mr. Castro.

They use that law, section 1325, to justify under the law, separating little children from their families. I want to challenge every candidate on this stage to support the repeal of section 1325. I agree with him on that issue, but folks should understand that the separation of children from families doesn’t just go on at our border. It happens in our communities as ICE are ripping away parents from their American children, spouses and the like. There are other provisions in the law that will allow you to prosecute people for coming over if they are dealing in drugs and other things. That's already established in the law. There is no need to repeat it.

Mr. O’Rourke has said that he wants to ensure there is a legal mechanism to address criminals crossing the border illegally. Senator Amy Klobuchar of Minnesota did not commit to a position, but appeared to have the same concerns as Mr. O’Rourke.

If we apprehend a known smuggler or drug trafficker, we’re going to ensure that they are deported and criminally prosecuted. I am happy to look at his proposal, but I do think you want to make sure that you have provisions in place that allow you to go after traffickers and allow you to go after people who are violating the law.

Bill DeBlasio, mayor of New York, interjected with a line that garnered applause from the audience.

We have to get under the skin of why we have this crisis in our system, because we’re not being honest about the division that’s been fomented in this country. The way that American citizens have been told that immigrants somehow created their misery and their pain and their challenges.

“Medicare for All” or “Public Option”?

Two candidates raised their hands when asked whether they supported abolishing private health insurance in favor of a government-run plan, often called “Medicare for all”: Senator Elizabeth Warren of Massachusetts and Mr. de Blasio.

Yes, I’m with Bernie on Medicare-for-all. Private insurance is not working for tens of millions of Americans.

Other candidates expressed support for a public option, in which everyone would have the option to buy a government-run health care plan, while still giving people the option to buy private insurance, at least in the immediate future.

We should give everyone in this country health care as a basic human right for free — full stop. But we should also give them the option to buy private insurance. We preserve choice by making sure that everyone has health care. No, I think that choice is fundamental to our ability to have everyone cared for. I also think if you look at other countries in the world who have universal health care, everyone of them has some form of a role of private insurance. I think it is a beginning and the way you start and the way you move to universal health care. When I am president of the United States, I’m not going to wait. We have to do the things immediately that are going to provide better care.

What Is the Greatest Geopolitical Threat to the United States?

Here is how each candidate responded (some gave more than one answer).

Climate Change Russia Donald Trump O’Rourke Warren de Blasio Inslee Castro Booker Iran China Nuclear Weapons Klobuchar Ryan Delaney Gabbard Climate Change Russia Donald Trump O’Rourke Warren de Blasio Inslee Castro Booker Iran China Nuclear Weapons Klobuchar Ryan Delaney Gabbard Climate Change Russia Donald Trump O’Rourke Warren de Blasio Inslee Castro Booker Iran China Nuclear Weapons Klobuchar Ryan Delaney Gabbard Climate Change O’Rourke Warren Castro Booker China Nuclear Weapons Ryan Gabbard Delaney Klobuchar Iran Donald Trump Inslee Russia de Blasio Climate Change O’Rourke Warren Castro Booker China Nuclear Weapons Ryan Delaney Gabbard Klobuchar Iran Donald Trump Russia Inslee de Blasio

What Makes Them Different

This question wasn’t asked, but several candidates found ways to highlight their accomplishments and life experiences to try to stand out.

In fact, Donald Trump, one of the first bills that he signed of the 34 he signed where I was the lead Democrat – okay that’s a first up here – was one that was about that, making sure minority community members could share in those jobs. You know, I’m very different than everyone else here on this stage. Prior to being in Congress, I was an entrepreneur. I started two businesses. I created thousands of jobs. I also want to say there’s something that sets me apart from all my colleagues running in this race and that is, for the last 21 years, I’ve been raising a black son in America. And I have had to have very very serious talks with my son Dante about how to protect himself on the streets of our city and all over this country. On climate change: “And I am the only candidate – frankly, I’m surprised – I’m the only candidate who’s made this commitment to make it the top priority.” I’m proud that I’m the only candidate so far that has put forward legislation that would reform our policing system in America and make sure that no matter what the color of your skin is that you’re treated the same, including Latinos who are mistreated too often times by police.

Where They Are From

Many candidates talked about their identities — citing their home states, their upbringing and their families.