Trump has made several comments about going after his political opponents and retribution. Asked to clarify what he meant, Trump replied, "Well, I said my retribution is going to be success."

He also contended that he's done nothing wrong despite his numerous criminal and civil cases.

Biden fired back contending that Trump's claims that he has the right to seek retribution is wrong. He then went after Trump over his various scandals.

"The crimes you are still charged with and think of all the civil penalties you have, how many billions of dollars ... and civil penalties? For molesting a woman in public for doing a whole range of things ... having sex with a porn star ... while your wife was pregnant? What would you be talking about? You have the morals of an alley cat," Biden said.

Almost 45 minutes into the debate, President Joe Biden finally referenced former President Donald Trump's recent felony conviction in New York.

During a discussion about the Jan. 6, 2021, insurrection, Biden said: "The only person on this stage that's a convicted felon is the man I'm looking at right now," referring to Trump.

538 ANALYSIS | How Trump's guilty verdict will impact the 2024 presidential election

Former President Donald Trump was convicted Thursday in his New York hush money trial.

Trump then sought to pivot from his own legal troubles by referring to Biden's son, Hunter, as a "convicted felon."

He was referencing the younger Biden's felony conviction this month on three firearms charges. Trump also repeated long-running claims related to the Bidens and Ukraine, a frequent attack point for Republicans.

In first half hour of debate, a raspy Joe Biden has delivered rambling answers that sometimes trail off as he defends his policies and record.

Donald Trump has countered with falsehoods on issues including the economy, abortion and NATO members' defense spending.

The two have also exchanged deeply personal attacks.

Debate questions are turning to Jan. 6, 2021, when supporters of then-President Donald Trump stormed the U.S. Capitol during the certification of the Electoral College vote count.

Trump was asked by host Jake Tapper whether he violated his oath to protect and defend the Constitution.

Asked about the Capitol attack on Jan. 6, 2021, Trump quickly pivoted to immigration and taxes. Pressed on his role, he said he encouraged people to act "peacefully and patriotically," then attacked former House Speaker Nancy Pelosi.

The rioters on Jan. 6 engaged in hand-to-hand combat with police and used makeshift weapons, including flagpoles, a table leg, hockey stick and crutch, to attack officers. Police officers were bruised and bloodied as they were dragged into the crowd and beaten. One officer was crushed in a doorframe and another suffered a heart attack after a rioter pressed a stun gun against his neck and repeatedly shocked him.

More than 1,400 people have been charged with federal offenses stemming from the riot. Of those, more than 850 have guilty people have pleaded guilty to crimes, including seditious conspiracy and assaulting police officers. About 200 others have been convicted at trial.