During the meat and potatoes of President Joe Biden's inauguration ceremony, Fox News's ratings fell by 77% compared to Donald Trump's in 2017, according to Nielsen.
The preliminary numbers from Nielsen don't paint the full picture, however.
Biden's inauguration slightly outperformed Trump's by 4% or 1 million viewers, according to the initial batch of ratings from Nielsen. A full count is expected to be released on Monday.
Part of why the Fox News dropoff appears so steep on a percentage basis is because the network broke the record for most inauguration viewers on a single channel back in 2017, averaging 10.5 million viewers.
This year's best performing TV outlet, CNN, came in at 9.9 million. Inversely from Fox, CNN performed worse in 2017 with just 2.61 million viewers on average.
While Fox News still has their 2017 record, they came in last place this year among the cable news networks and major TV channels, with just 2.74 million viewers on average during the midday ceremony.
Another factor in the viewership swings between Fox News and the other cable channels is the partisan breakdown of their viewership.
A Pew Research study from 2020 found Fox News' viewership to be the most conservative in the space, with their audience about as equally partisan as MSNBC's.
Pew Research
CNN received more respondents self-identifying as Republican or lean-Republican, but Pew found that their audience still skews heavily to the left.
Right after Fox News's programming for the inauguration wrapped up in the late afternoon, their opinion panel show, "The Five," shot up from the previous hour's viewership of 1.9 million to 3.13 million, according to Nielsen.
"The Five" consistently punches above its weight in the 5 p.m. ET hour.
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By later in the evening, Fox's main primetime lineup of Tucker Carlson, Sean Hannity, and Laura Ingraham brought viewership back to its normal levels. Carlson landed 3.7 million viewers, Hannity got almost 3.2 million, and Ingraham pulled in about 2.4 million.
Both totals are typical for the opinion hosts, but unlike most nights, CNN and MSNBC outperformed Fox News in primetime with their special coverage of the Biden inauguration's singers and special guests. Carlson, Hannity, and Ingraham only briefly ran footage from the events, choosing instead to stick with their regular formats.