Outside of the segment on Trump's indictments and his behavior on Jan. 6, it's been a bit surprising that there's been little discussion of him otherwise. There've been a few references to actions taken prior to Biden taking office, indirectly involving Trump, but not much specifically about him. That has turned this debate into something of an alternative universe where these are the main eight candidates, not the eight who are badly trailing the main guy not in the room.
-Analysis by Geoffrey Skelley of FiveThirtyEight

Yeah, Maya, I am surprised Trump didn’t come up more. With him not on stage, I actually thought it would be easier for the candidates to swipe at him, since there was no risk of him punching directly back. But with some notable exceptions, like Christie and Hutchinson (and even then, only on a couple occasions), the candidates showed little interest in hammering away at the primary front-runner. I think that’s a questionable strategy since none of these candidates will be able to earn majority support in the primary without stealing some of it from Trump.
-Analysis by Nathaniel Rakich of FiveThirtyEight

Sixty-eight percent of Americans think the government is withholding information about UFOs, and three-fourths think there is some form of life on other planets. The number of Americans who suspect UFOs have been spotted has also increased, and 41 percent believe that some spotted UFOs are alien spacecraft. This has only been increased in recent years with Navy pilots reporting strange sightings over the past decade, along with recent congressional hearings about the issue.
-Analysis by Monica Potts of FiveThirtyEight

Christie was seen smiling and shaking his head as Fox News moderator Martha MacCallum began to ask about UFO ecounters.

"I get the UFO question? Come on, man!" Christie said.

"I think it's horrible that just because I'm from New Jersey, you asked me about unidentified flying objects and martians," he continued. "We're different but we're not that different."

President Joe Biden's reelection campaign was noncommittal Wednesday when asked if he would debate the ultimate GOP presidential nominee.

"We have not had a conversation about that at all," Biden campaign co-chair Cedric Richmond told reporters during a press conference Wednesday. "I'm sure one day we will. But it's not today and I don't have any news on that. But what we're going to continue to do is continue to govern because Vice President [Kamala] Harris and President Biden have a job to do and they take it serious. So when we have news on that, we’ll let you know."

Biden and his allies have gone after the entire Republican primary field, tying them all to the "MAGA" brand of former President Trump.

However, the future of presidential general election debates is up in the air after the Republican National Committee last year voted to quit the Commission on Presidential Debates, the non-partisan group that has put on general election debates since 1988.

Biden's campaign also defended its decision to not engage in any Democratic primary debates, boasting that the president, as the incumbent, is the presumed nominee despite facing challenges from Robert F. Kennedy Jr. and Marianne Williamson.

-ABC News' Tal Axelrod