President Donald Trump and Democratic nominee Joe Biden squared off Thursday at Belmont University in Nashville, Tennessee, in the second and final debate. The debate comes 12 days before Election Day, with over 35 million Americans having already voted, and with the incumbent lagging behind Biden in most general election polls.

The debate format included muted microphones after several heated exchanges sullied the first debate on Sept. 29. 

The two candidates touched on several key topics including fighting the COVID-19 pandemic and climate change.

A strong performance by Trump was considered imperative to recover from sagging poll numbers in several swing states. The electoral map shows Trump trailing or in a tight battle in must-win states such as Michigan, Pennsylvania and Wisconsin, as well as Arizona, Florida and Ohio.

Despite fewer interruptions compared to the first debate, there were several heated exchanges, including Trump's comments on race. 

"Nobody has done more for the black community than Donald Trump. And if you look, with the exception of Abraham Lincoln, possible exception, but the exception of Abraham Lincoln, nobody has done what I’ve done," Trump said.

Another contentious exchange included Biden slamming Trump for saying that the Democrats' environmental plan cost $100 trillion. 

So who won the debate?

There were several different opinions. 

NBC News anchor Andrea Mitchell spoke highly of Biden's performance. "I think in this debate, the care and empathy that Joe Biden showed — and it was the best debate I've ever show Joe Biden do — I think he rose to the challenge, he didn't get rattled," she said after the debate.

Rick Santorum, a former Republican senator from Pennsylvania, spoke highly of Trump while on a CNN panel.

"Trump I think very effectively said, 'Who built the cages?'" Santorum said.

Former Democrat campaign manager David Axelrod said that Trump "was much, much better" in the second debate than the first debate. However, Axelrod noted that there were moments for Trump "that remind people exactly what bothers them about him."

Civility was a key issue entering the debate. Echoing comments from NBC News analysts, Judy Woodruff of PBS NewsHour noted that the debate was more substantive than the previous debate.