By Christine Kearney
NEW YORK (Reuters) - Howling wind, driving rain and potential damage in New Orleans from Hurricane Isaac hasn't yet dampened U.S. Republican convention media coverage, but early TV ratings proved only so-so while many people instead "tuned in" to social networks.
Republican fears that Isaac's battering of the U.S. Gulf Coast would steal the spotlight eased on Wednesday, a day after a key speech by Ann Romney, wife of Republican presidential candidate Mitt Romney, stole the show from New Jersey Governor Chris Christie.
But the biggest problem for the Republicans was less the hurricane and more dwindling interest in convention-watching by the general public, experts said.
"Isaac is sucking out a lot of the oxygen but that's because there wasn't much oxygen in the first place," said Sherry Bebitch Jeffe, senior fellow at the University of Southern California's Price School of Public Policy. "Voters and certainly the media are aware these conventions have become hour-long infomercials. There is very little suspense."
Ahead of Tuesday, news of Isaac's path toward the U.S. Gulf Coast revived memories of Hurricane Katrina's destruction seven years ago and threw a spotlight on something the Republican Party would rather forget in its convention week -- the botched relief efforts under George W. Bush, the last Republican president.
But even as some networks moved their anchors from the convention in Tampa to Isaac's landfall in New Orleans to cover both events, those interested in politics tuned in to hear Ann Romney personalize her husband and Christie tackle the Obama White House -- whether on TV or the Internet.
Preliminary data from Nielsen Media Research showed that more than 20 million Americans watched TV coverage of the Republican convention on Tuesday night in the 10 p.m. EDT hour when Ann Romney took the stage. By contrast, 37.6 million people watched Democratic President Barack Obama's most recent State of the Union speech.
About half of the convention's TV audience watched on cable news networks, as Fox News took the lion's share with an average 6.9 million viewers - triple its usual audience. About 11 million watched on broadcast networks NBC, ABC and CBS, which reduced coverage this year to just one hour per night.
Comparisons to the equivalent night in 2008 were not available, but TV audiences for U.S. political conventions have fallen steadily in the last 10 years, with the exception of 2008 when little-known Republican Sarah Palin captured attention.
CONVENTION COVERAGE CHANGES
But the story is different on the Web where, social media experts said, Americans are watching the convention differently from four years ago when Twitter and Facebook were little known.
Thousands of people visited social media sites to follow the convention live across Facebook, Twitter, Google+ and YouTube. Topics such as #GOP2012, #RNC and #Romney were high-trending on Twitter, alongside hashtags for Hurricane Isaac.
Judging by both pundits and tweets, Ann Romney's rousing, high-stakes speech lined with simplistic talk of love was a show-stopper, succeeding in its goal major of connecting Republicans with female voters and humanizing husband Mitt Romney.
"I can't remember a better convention speech by a would-be first lady than Ann Romney delivered," wrote David Frum of The Daily Beast. "Ann Steals the Show" ran the headline on The Huffington Post and CNN delivered the caption "Ann Romney wows the RNC" and quoted reaction as "electric."
An opinion piece in The New York Times said she had less impact when comparing herself to mothers struggling to raise children, but connected more in her speech's second half when speaking realistically about her husband privileged background.
Ann Romney gathered the most Twitter mentions of the night, peaking at a high of 6,195 tweets per minute at the end of her speech when her husband joined her on stage.
The Twitter Political Index measuring tweeters' feeling about a candidate on scale of 1 to 100, 1 being not favorable, saw Ann Romney's score rise from 45 to 83 after the speech.
Facebook and CNN's election insights website also showed a 58 percent increase in users talking about Mitt Romney on Tuesday with the number peaking during Ann Romney's speech.
And traditional media outlets such as the Washington Post, New York Times, CNN and Reuters added to social media coverage, live tweeting, Facebooking, blogging, streaming video, and giving former TV watchers more ways to keep up to date.
The Republican National Committee's own live stream on YouTube has attracted 292,000 views since Monday and has some 3,200 subscribers.
Christie's speech was the second most tweeted-about event at the convention Tuesday, peaking at 6,079 tweets a minute.
Unlike Romney, reactions were more mixed. Fox News praised the speech but included debate about whether the governor, who focused more on his achievements in New Jersey than expected, was hard enough on Obama.
(Additional reporting by Jill Serjeant and Piya Sinha-Roy; Editing by Bob Tourtellotte, Mary Milliken and Lisa Shumaker)