The 2016 race for the White House is the ratings gift that keeps on giving for cable news.
Fox News Channel led on the night with 4.46 million viewers from 8 to 11 p.m. Eastern time, up 70% from the 2.63 million viewers who watched its Iowa caucuses coverage in 2012, the previous high.
For the Record
Feb. 2, 4:15 p.m.: An earlier version of this story reported the increase in viewers for Fox News Channel's coverage was 81% over 2012. That figure is the increase over the network's 2008 coverage.
FNC's audience peaked from 10:30 to 10:45 p.m. Eastern as 5.1 million viewers watched the speech of Sen. Marco Rubio, the third-place finisher on the Republican side.
FNC's coverage was anchored by Bret Baier and Megyn Kelly, the breakout TV news star of the campaign thanks in part to Republican candidate Donald Trump. The real estate mogul, who finished second in the caucuses despite having a lead in the polls, has accused Kelly of being unfair towards him since her tough questioning at the first GOP primary debate on Aug. 6.
Trump's public attacks on Kelly, which ultimately led to his bowing out of the last GOP primary debate that aired Jan. 28 on FNC, have raised the anchor's profile. She has been booked as a guest on the post-Super Bowl edition of "The Late Show with Stephen Colbert" airing Sunday.
Trump's presence in the first six Republican primary debates lifted most of the events to record-high ratings, so it's likely that viewer interest in his campaign is spilling over to coverage of the voting results.
CNN, which has invested heavily in political coverage, finished a strong second on the night with 3.73 million viewers, up 185% from 2012 and topping its previous high for Iowa caucuses coverage, set in 2008 (2.2 million viewers).
CNN led among viewers in the 25-to-54 age group that advertisers seek with news programming, averaging 1.39 million. FNC was second in that demographic group, with 1.16 million viewers.
MSNBC, which had Brian Williams and Rachel Maddow in the anchor chairs for its coverage, was a distant third for the night with 1.97 million viewers overall and 592,000 in the 25-to-54 demographic. Although the channel's viewership was higher than for previous Iowa caucuses, the gap with second-place CNN widened considerably.
MSNBC was just 10% behind CNN in prime time audience for the Iowa caucuses in 2012. On Monday, CNN had a 90% advantage. CNN's lead in the 25-to-54 demographic was 135%, compared with 60% in 2012.