HOUSTON (CBSDFW.COM) — All of the top 10 democratic presidential candidates in the polls squared off together for the first time at a high-stakes debate in Houston Thursday night.

They discussed healthcare, illegal immigration, race and what to do after the deadly El Paso and Odessa mass shootings.

A lot of the talk centered on gun control and whether assault style rifles should be banned.

Former Texas Congressman Beto O’Rourke had perhaps the most forceful answer on a mandatory buy-back.

“Because so many other people were shot by that AR-15 in Odessa and Midland, and there weren’t enough ambulances to get to them in time. Hell yes, we’re going to to take your AR-15, your AK-47. We’re not going to allow it to be used against our fellow Americans anymore,” O’Rourke said.

Former Vice President Joe Biden said he doesn’t think a president can use an executive order to ban assault style rifles because it’s unconstitutional.

In response, California Senator Kamala Harris told Biden he should say, “Yes we can”, referring to former President Obama’s campaign slogan.

The candidates had the most disagreements over healthcare reform, and at one point, it became combative when former San Antonio Mayor and HUD Secretary Julian Castro went after Biden’s plan.

Castro said he is fulfilling the legacy of Barack Obama, and Biden is not.

Biden responded, “That’d be a surprise to him.”

South Bend, Indiana Mayor Pete Buttigieg said the debate is reminding everyone of what “they cannot stand about Washington.”

“This is why presidential debates are becoming unwatchable,” Buttigieg said. “Scoring points against each other. Poking at each other. Telling each other my plan, your plan.”

Castro swiftly replied, “That’s called a Democratic Primary Election. That’s called an election. That’s an election you know? That’s what we’re here for.”

But Minnesota Senator Amy Klobuchar said a house divided cannot stand.

Though, the democratic candidate did agree on many other issues.

Some analysts say O’Rourke had some good moments, but with his poll numbers lagging nationally, the question is will the debate give him a boost.

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