"I turn on one of the networks, and they show an empty field," Trump said during a speech in the weeks after his ceremony, slamming the media for, in his mind, massively understating the size of his inaugural crowds.
"I'm like, wait a minute. I made a speech. I looked out, the field was, it looked like a million, million and a half people."
Spicer, who didn't even last a year in his role as press secretary, at the time called the reporting of audience numbers "attempts to lessen the enthusiasm for the inauguration" that were "shameful and wrong".
It was what The Atlantic deemed "the first lie of the Trump Presidency".
The inauguration numbers aren't the first time Biden beat his predecessor, who has frequently mocked TV personalities for any evidence of sliding Nielsen figures, in a ratings battle. In October, the pair went head-to-head in town-hall-style events.
The ABC broadcast featuring Biden notched 15.1 million viewers, while just 13.5 million Americans watched Trump across NBC, MSNBC and CNBC.
One thing the pair do have in common, however, in terms of their inauguration viewership: neither posed any competition to former President Barack Obama's first address. According to Nielsen, more than 51 million people watched Obama's opening speech in 2009.
It's worth noting that Biden's numbers likely got a boost on January 20 due to more people being at home and available to watch, with the Covid-19 pandemic keeping many from workplaces and schools closed.
And while there may not have been the physical crowds of inaugurations past, that didn't stop the new President's ceremony from being any less powerful.
Shortly after Biden wrapped up his inaugural address – which called for an era of unity and reconciliation – CNN's Wolf Blitzer declared that the "world witnessed democracy withstand one of its greatest tests".
Meanwhile MSNBC's Brian Williams said he "gave the kind of inaugural address our presidents used to give".
"I've been listening to these inaugural addresses since 1961," Fox News Sunday anchor Chris Wallace said.
"I thought this was the best inaugural address I ever heard."
