The first presidential debate of the 2024 campaign cycle drew about 51.3 million people, according to the media analytics company Nielsen, a sharp drop from previous debates and the smallest audience since a 2004 debate between John Kerry and President George W. Bush.

Nielsen’s audience estimate came in slightly above host CNN’s figure. The cable news company said Friday that 47.9 million people watched the debate between Joe Biden and Donald Trump across broadcast and cable TV as well as streaming.

While still a sizable TV audience, Nielsen’s estimate represents an approximately 30% drop in viewership from the first Biden-Trump debate in 2020, which drew 73 million viewers. At 51.3 million people, the estimate puts the most recent debate just ahead of the third Bush-Kerry debate but behind all debates from the 2008, 2012 and 2016 campaigns, according to data from Nielsen’s election hub.

Still, the debate was the highest-rated program in the network’s history, CNN said, as well as its most livestreamed. It’s also the most-watched nonsports program of the year so far, the network said.

In addition to CNN, the debate was simulcast across all major news networks including NBC, ABC, CBS and Fox; PBS and C-SPAN; and many of the broadcast groups’ sister networks like MSNBC and Fox Business. It was also available for streaming on a host of digital platforms.

The debate has sparked a wave of discussion about whether Biden could step aside as the Democratic candidate for president, though replacing him would be challenging.

This is a developing story. Please check back for updates.