The first and only showdown between Indiana Gov. Mike Pence and Sen. Tim Kaine of Virginia attracted an average audience of 37 million viewers Tuesday, making it the smallest audience for a vice presidential debate since 2000.
Pence, the running mate of Republican presidential nominee Donald Trump, and Tim Kaine, Democratic nominee Hillary Clinton's No. 2, were not expected to be the same ratings draw as the top of the ticket.
The Sept. 26 meeting between Trump and Clinton had an average audience of 84 million viewers, a record for a presidential debate, according to data from Nielsen.
The most-watched vice presidential debate ever was between Joe Biden and Sarah Palin during the 2008 campaign, which had an average audience of 69.9 million viewers.
Based on the early data, Kaine vs. Pence is down about 28% from the 2012 vice presidential debate when 51.4 million viewers watched Biden face off against his Republican challenger, Rep. Paul Ryan of Wisconsin. The last vice presidential debate to score under 40 million viewers was the meeting between Republican Dick Cheney and Democrat Joe Lieberman in 2000, which had 29 million viewers.
NBC had the largest audience for Tuesday's debate with 7.02 million viewers. CBS was second with 6.46 million, followed by ABC (6.14 million), the Fox broadcast network (2.2 million) and PBS (1.47 million).
On cable, Fox News Channel led with 6.08 million viewers, followed by CNN (4.16 milion), MSNBC (3.12 million) and Fox Business Network (392,000).
The debate was moderated by Elaine Quijano, an anchor for CBSN, the digital channel operated by CBS News.