But she didn't put to rest the issue of whether NBC News was wise to include the host of MSNBC's most popular opinion show as a questioner. Some journalists and conservative critics have said this violates a traditional, if frayed, distinction between news and opinion. Maddow also faced the issue this spring when The New York Times pulled its reporters as regular guests on her show, saying it would enforce its rule of not letting its journalists appear on opinion programs.
Maddow played it straight during the two debate nights, asking 15 questions and addressing 12 of the 20 candidates onstage. She brought up climate change, guns, abortion policy and the Supreme Court. She wanted to know what Amy Klobuchar had done to help blacks and Latinos, and asked Joe Biden to address his vote in favor of the Iraq War.
When Maddow asked Sanders if his feelings had changed since a 2013 interview in which he said states should make decisions on gun policy, Sanders said, "that's a mischaracterization of my thinking." Responded Maddow: "It's a quote of you."
In the wake of a police shooting of a black man in South Bend, Indiana, Buttigieg was asked why the percentage of black police officers there had not changed during his time as mayor. "Because I couldn't get it done," he replied.
NBC News executives and Maddow declined to publicly address the issue of her involvement, except to point out that Maddow helped moderated a debate between Sanders and Hillary Clinton in 2016. NBC distributed reviews and tweets of last week's performance, including Washington Post columnist Jennifer Rubin tweeting that some critics owed Maddow an apology. "She might have been the best of 5 moderators," Rubin said.
"Her questions were focused, sharp, short and provocative," said Tom Bettag, a longtime news producer who now teaches journalism at the University of Maryland. "She is very good as a questioner. I didn't see anything in there that showed bias."
Yet he questioned whether it sent the wrong message to include Maddow coming off the 2016 election, when many in the media missed or underestimated the views of Trump supporters. "Let's not have the public assume that we're definitely leaning in one direction," he said.
NBC and MSNBC clearly have different missions, he said. In choosing the moderators onstage in Miami, NBC News seemed intent on exposing different parts of its operation by including "Nightly News" anchor Lester Holt, "Today" host Savannah Guthrie, "Meet the Press" moderator Chuck Todd, Telemundo's Jose Diaz-Balart and Maddow.
Maddow's participation fit right into the frequent media criticism from Fox News' conservative commentator Sean Hannity. He said she and Todd "asked their Democratic friends on the stage to indulge their far-left conspiracy theories.
"Me, Rush (Limbaugh), (Mark) Levin, how about (Bill) O'Reilly?" Hannity said. "How about all four of us? We'll do the next debate." There are important distinctions: Maddow's show is reporting-based and she hasn't jumped onstage to speak at a campaign event, as Hannity has. Fox has not included its prime time stars Hannity, Tucker Carlson or Laura Ingraham in Democratic candidate forums (it has not been awarded a debate), but Megyn Kelly helped moderate GOP debates last cycle.
Maddow "performed exactly as expected," said Tim Graham, director of media analysis for the conservative watchdog Media Research Center. While she addressed some legitimate issues, many conservatives objected to the way some questions were framed with a liberal perspective. He cited Maddow asking Washington Gov. Jay Inslee if Miami can be "saved" from climate change, and asking former U.S. Rep. John Delaney if Trump should be prosecuted for crimes after leaving office.
There is, however, the view that having someone attuned to one political perspective may add value. Philip Klein, executive editor of the conservative-friendly Washington Examiner, wrote before the debate that Maddow's participation might be a good idea if she didn't ask softball questions.
He said Tuesday that Maddow did a perfectly fine job. "As somebody tapped into the thinking of ideological liberals, she was able to press candidates on a number of areas of concern to this key voting bloc," he said.
Similarly, the issues that get the most attention on Fox News can give their town halls a markedly different flavor than those elsewhere. Fox's forum with Julian Castro, for example, was held on the day that Trump was in the news for an ABC News interview that discussed accepting opposition research from foreign governments in 2020. Fox opened with two questions from news anchors Bret Baier and Martha MacCallum about whether it was different from a dossier of information compiled for Democrats on Trump four years earlier.
Both Buttigieg and Kirsten Gillibrand were asked on Fox about their positions on third-trimester abortions, and one audience member pointedly asked Castro: "Do you determine the number of people pouring into our country to be a national crisis?"
Still, having moderators with clear ideological identities could be a distraction for news organizations. "Having an opinion person doing it is a very tough line to cross, even though (Maddow) did very well," said Kate O'Brian, a news consultant and former executive at ABC News and Al Jazeera.
"As news people we wouldn't look at Fox News doing something like this favorably," she said. "So we have to look at it the same way for all media organizations."