The drop in viewership for Tuesday's event, which compared to 24.7 million in 2016, drew 19.2 million viewers across 10 television networks and showed Vice President Joe Biden receiving the formal nomination to run for president as Democrat, followed a similar drop of about 24 percent in DNC's first-night viewership compared to four years ago.
Monday's event drew 19.7 million viewers, while the first night of 2016 had an audience of 26 million.
Nielsen figures only include traditional television broadcasts and not online and streaming broadcasts, which are becoming increasingly popular forms of content consumption by US audiences, and may be a factor in the decline of the audience.
Other assumptions include the fact that the convention was held virtually due to the coronavirus outbreak and thus lacked prior coverage in venues, which typically pique interest from the public.
Biden, a six-term senator and a two-time unsuccessful presidential candidate, is to deliver his acceptance speech Thursday night in a nearly empty convention hall near his home in Delaware.
On Tuesday, Biden's wife of more than 40 years, Jill Biden, spoke of her husband in deeply personal terms, describing the longtime politician as a man of empathy and resilience.
"There are times when I can't imagine how he did it, how he put one foot in front of the other and moved on," she said. But I always understood why he did it. He does it for you.”
“I will probably give my speech at the White House because it is a great place. It's a place that makes me feel good, makes the country feel good, "Trump told reporters.
"We will possibly do it outside in one of the gardens, we have several gardens, so we could do it outside considering the Chinese virus" the president continued, referring to the origin of the coronavirus and the social distancing measures that are in place to fight the potentially deadly bug.
“We could have a good group of people. It is very large, a very large garden. We could have a great group of people,” he added when asked if there would be a large number of supporters when Trump formally accepts the Republican nomination.