NEW YORK — If anything could slow the inexorable decline of evening news viewership, it should have been this year's riveting presidential campaign, which produced a ravenous appetite for political news.
The cable news networks benefited mightily during the race, more than doubling their prime-time audiences this fall. And some broadcast news programs saw big gains: "60 Minutes," up 12% this season, attracted 25 million viewers Sunday for its interview with Barack and Michelle Obama, the largest audience for a television program this season.
But the overall number of people watching the network evening newscasts actually shrank slightly in the last months of the presidential campaign, despite the programs' heavy political focus -- down 280,000 viewers since Sept. 22 compared with the same period last year, according to an examination of Nielsen Media Research data.
Of the three programs, the top-rated "NBC Nightly News" was the only one to register an uptick in audience, growing 1% to 8.37 million viewers. ABC's "World News" fell 2% to 8.2 million viewers while "CBS Evening News" dropped 3% to 6.1 million viewers.
The contraction of the audience at a time when viewers were aggressively seeking news speaks to the challenge the programs face in a landscape increasingly cluttered with media choices.
Once the country's dominant news platforms, the three flagship network newscasts found themselves jockeying this season with cable channels and Internet sites to deliver the freshest political updates.
"There was just a lot of coverage out there, and with the 24/7 nature of the cable networks, you could hear whatever you wanted to hear at any time," said Andy Donchin, director of media investment for the ad-buying firm Carat. "With all the choices and options, continual erosion is inevitable."
News executives argued that the relatively small drop-off in viewers this season speaks to the lasting strength of the 30-minute broadcasts.
"The fact that, given the competitive environment, we're holding our audience over last year is significant," said Jon Banner, executive producer of "World News." "I don't think we get the big bumps that you've seen in some other media, but we don't get some of the big drops they're getting now."
The cable news networks -- which challenged the broadcast networks' dominance on many big political nights this year -- saw their prime-time viewership fall substantially during the first week after the election. (All three had higher ratings than the same week last year.)
Still, there's no question that cable news saw the most momentum during the campaign. NBC executives credited having a sister cable network, MSNBC, on which to showcase their talent in part for the evening newscast's 8% gain among viewers ages 25 to 54, those most coveted by advertisers.
"I think that identification with these reporters over the course of the day just benefits everybody," said Bob Epstein, senior broadcast producer of "NBC Nightly News."
This year's campaign was supposed to serve as a showcase for the network anchors, all of whom were making their presidential election debut. But Brian Williams, Charles Gibson and Katie Couric did not dominate the 2008 race the way their predecessors did in past elections.
The anchor who attracted the most buzz was Couric, who conducted a series of much-talked-about interviews with Alaska Gov. Sarah Palin. For all the attention, however -- including a parody on "Saturday Night Live" -- "CBS Evening News" still suffered the biggest drop in viewership.
"I don't have an explanation," said Sean McManus, president of CBS News. "I think we did a really, really good job, and I would be lying if I didn't say the ratings were disappointing."
Part of the challenge is the early hour the newscast airs, he said, "an increasingly more difficult time period for people to sit down in front of their television sets."
It's been a chronic issue as American lifestyles have changed. Since 1991, the combined audience of the three broadcasts has dropped from 36.7 million to 22.7 million.
That's still a substantial audience in a fragmented media universe, noted Donchin, who buys ads on all three programs for his clients.
"Even with the loss of viewers, we still see the evening news telecasts as an important place to be," he said. "They're still the tallest midget in the room."