Former Vice President Joe Biden had a questionable response to the moderators about what his first action would be as president.

In the second half of the debate, MSNBC moderator Chuck Todd explained that President Obama wanted to address healthcare and climate change in office and only managed to tackle one of them. All ten of the candididates were asked what "first issue" they would take on from the Oval Office.

The answers varied from one candidate to the other, some like Sen. Michael Bennet, D-CO, pointed to climate change while Rep. Eric Swalwell, D-Calif, invoked gun control.

But when Biden's turn was up, he began by defending his former running mate.

SWALWELL ZINGS BIDEN ON HIS AGE, CALLS ON HIM TO 'PASS THE TORCH'

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"I think you so underestimated what Barack Obama did," Biden said. "He's the first man to bring together the entire world, 196 countries to commit to the deal with climate change. Immediately."

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The Democratic frontrunner then went on to answer the question... but answered with something that should have been done by the time he is sworn in as president.

"The first thing I would do is make sure that we defeat Donald Trump. Period," Biden confidently declared.