But an awkward “halftime show” and seemingly unconnected YouTube videos appeared to undercut what should have been NBC’s moment to celebrate the veteran savvy and old-school gravitas of its two dignified moderators.

NBC partnered with YouTube for the debate, which enabled the network to livestream the debate on the video-streaming service. The partnership also provided top billing on the Google.com and YouTube.com home pages, since Google owns YouTube. That probably offered a boost in viewership for what most observers expected to be a comparatively low-rated event, thanks to the Democratic National Committee’s much-criticized decision to schedule debates on weekends near holidays.

NBC probably also saw YouTube as a way to incorporate social media into the broadcast, the way other networks partnered with Facebook and Twitter. But while Facebook and Twitter are objective tools for measuring voter sentiments, slickly produced videos didn’t feel like a particularly useful way of capturing the zeitgeist.

So NBC’s viewers were treated to showboating questions from YouTube “creators” — professional YouTube show hosts — that offered absolutely nothing different or surprising in terms of substance, except to advertise the cheeky personalities of the creators. To be sure, the creators have millions of followers. But whether those millions of (likely young) followers tuned in to watch their favorite YouTube celebrity ask a question on a Sunday night during a three-day weekend is yet to be known. (It didn’t help that Sanders couldn’t hear the first video about policing, obliging Holt to re-read the question word for word.)

Later, after Holt introduced a YouTube question on climate change and U.S. reliance on oil that was delivered as a cartoon, critics lit up Twitter.

“All future questions should be in the form of cartoons,” quipped political analyst Jeff Greenfield.

“Did they just air a cartoon about climate change in a debate between candidates running for the American presidency?” tweeted The Israel Project’s Omri Ceren.

“Just figured it out. This whole #DemDebate is a TV network’s attempt to make social media stars look like buffoons,” The Daily Beast’s Noah Shachtmann tweeted.

At the midpoint of the debate, NBC cut to “Meet the Press” host Chuck Todd for some middebate analysis, and then to Holt and Mitchell on stage for some stilted exchanges.

“Anyone else think that #DemDebate halftime show needed a band?” tweeted Republican presidential candidate Sen. Rand Paul.

By contrast, social media was quite kind to the moderators, doling out praise for Holt and Mitchell for asking tough questions and then stepping in quickly to try to tease out differences between the candidates, who often seemed to start their answers with “I agree” — a quirk that marred previous Democratic debates.

Holt kept the ship on course with a strict hand on the timer while asking illuminating questions, such as one directed at Hillary Clinton about why Sanders was beating her 2 to 1 among younger voters.

“Lester Holt is doing a great job. No softballs so far,” tweeted New York Times reporter Nick Confessore.

“Lester holt is PREPARED,” tweeted Deep Focus CEO Ian Schafer.

Mitchell won praise for pressing Sanders several times to answer how he would pay for his proposals and for her widely probing questions about the Middle East, including an illuminating exchange with Clinton about the Obama administration’s response to the Assad regime’s use of chemical weapons in Syria. Clinton seemed to suggest she’d have been tougher on Assad.

“Excellent question from Andrea Mitchell to Clinton on the ‘red line’ in Syria. Shows why it’s so hard to run as a legacy candidate,” tweeted Yahoo’s Matt Bai.