Debate details

When: Wednesday, 8 p.m. (main stage) and 6 p.m. (kids' table)

Location: Ronald Reagan Presidential Foundation and Library in Simi Valley, Calif.

Moderators: CNN host Jake Tapper, CNN correspondent Dana Bash, conservative radio host Hugh Hewitt.

Candidates, in order of national polling support: Main stage — Donald Trump, Jeb Bush, Scott Walker, Ben Carson, Ted Cruz, Marco Rubio, Mike Huckabee, Rand Paul, John Kasich, Chris Christie, Carly Fiorina. Kids' table — Rick Santorum, Bobby Jindal, George Pataki, Lindsey Graham.

Fact-checking candidates

How have the presidential hopefuls who will appear in Wednesday's second GOP debate fared on the Truth-O-Meter? Find out here: www.facebook.com/politifact.georgia?fref=ts&ref=br_tf.

Fact-checking candidates

How have the presidential hopefuls who will appear in Wednesday's second GOP debate fared on the Truth-O-Meter? Find out here: www.facebook.com/politifact.georgia?fref=ts&ref=br_tf.

Fact-checking candidates

How have the presidential hopefuls who will appear in Wednesday's second GOP debate fared on the Truth-O-Meter? Find out here: www.facebook.com/politifact.georgia?fref=ts&ref=br_tf.

Prime-time viewership

The number of viewers, in millions, for each 24-hour cable news network:

2012 / 2014

Fox News 1.9 / 1.7

MSNBC 0.8 / 0.6

CNN 0.6 / 0.5

Fact-checking candidates

How have the presidential hopefuls who will appear in Wednesday's second GOP debate fared on the Truth-O-Meter? Find out here: www.facebook.com/politifact.georgia?fref=ts&ref=br_tf.

Prime-time viewership

The number of viewers, in millions, for each 24-hour cable news network:

2012 / 2014

Fox News 1.9 / 1.7

MSNBC 0.8 / 0.6

CNN 0.6 / 0.5

Fact-checking candidates

How have the presidential hopefuls who will appear in Wednesday's second GOP debate fared on the Truth-O-Meter? Find out here: www.facebook.com/politifact.georgia?fref=ts&ref=br_tf.

There are few must-watch events anymore in television news.

Atlanta-based CNN has one in Wednesday’s Republican presidential debate, a major journalistic, technical and business challenge likely to produce the network’s biggest audience ever, given the record-shattering 24 million people who watched Donald Trump and company spar on Fox News in August.

Well before the lights go on, CNN faced controversy in staging the highly profitable double-barreled event. It tweaked its rules to move businesswoman Carly Fiorina out of the “kids’ table” debate and expand the prime-time field to 11 after Fiorina and her backers complained. But CNN so far has not responded to Trump’s request that its profits from the debate’s lucrative ad sales go to veterans charities.

The scrutiny comes at a time when CNN is pushing to reverse a years-long ratings slide and find its niche as the non-ideological news network in between Fox News and MSNBC.

“It’s a terrific showcase for them, and if they do well with the debate, it’s certainly the sort of thing that might prompt people to give them another look,” said Dan Kennedy, a Northeastern University journalism professor.

In recent days the news team honed questions for moderators Jake Tapper, Dana Bash and Hugh Hewitt — a conservative radio host with CNN's debate partner, Salem Media Group. Meanwhile, the network's crew assembled a stage and backdrop with blunt symbolism: a retired Air Force One at the Ronald Reagan presidential library in Simi Valley, Calif.

CNN Washington bureau chief Sam Feist said the network's goal is to get the candidates to engage each other, rather than making the story about the moderators. In the first debate Trump took offense to tough questioning from Fox News' Megyn Kelly, later making comments about Kelly that many perceived to be misogynistic. As a result, Trump was dis-invited from the conservative RedState Gathering in Atlanta.

Soon, it seemed CNN was Trump’s favorite network, with the real estate magnate frequently calling in to its shows.

But Trump was still eager to needle CNN and show his power. In a Sept. 8 open letter to network President Jeff Zucker, Trump pointed to reports that CNN was charging up to $200,000 for a 30-second debate ad slot — 40 times its usual rate.

So Trump proposed the debate’s Trump-boosted proceeds should go to veterans charities, rather than the network’s pockets.

Visiting Washington the next day for a rally against the Iran nuclear deal, Trump was asked by a CNN reporter whether he, the prolific deal-maker and profit generator, would do such a deal if he were in Zucker's shoes.

“If I were Jeff Zucker, I’d think about it,” Trump replied. “Maybe I have a bigger heart than he does. I want to give the money to the vets.”

Asked by The Atlanta Journal-Constitution about Trump’s effect on ratings, Feist replied that the network sees a boost whenever any “top-tier candidate” is on.

The other big development out of the first debate was the rise of Fiorina.

Fox, like CNN, broke the field into two, limiting its prime-time debate to 10 of the 17 major candidates then in the race and ranking them based on national polls. Fiorina performed well in the earlier debate and saw her poll numbers rise. But they were not enough to offset polls taken before the Fox News debate, so Fiorina and her supporters launched a public pressure campaign against CNN to let her on the big stage.

Feist said the network decided to change the criteria in order to “capture the current state of the race which, frankly, did change at that first debate.” But he did not want to punish anyone by bumping them off the big stage, so now CNN will make room for 11.

The man in the middle once again will be Trump. Former CNN Washington bureau chief Frank Sesno, now director of the School of Media and Public Affairs at George Washington University, said the network should try to keep the billionaire from dominating.

“This will be a very important moment,” Sesno said. “Because the question will be whether, in the way that CNN conducts the debate, it in any way changes the dynamic, changes the equation, makes it somehow less about Donald Trump and more about the others or the issues.”

Trump has already complained about "gotcha questions" from Hewitt, who stumped Trump in a recent interview by asking him about Middle East military leaders.

Sesno said the moderators should have no concerns about backlash for sharp questioning.

“Because Fox was as tough on the candidates as they were, they helped inoculate CNN” from bias questions, Sesno said.

CNN was the original 24-hour news network, but in 2002 it was overtaken in total viewers by Fox News, which draws a loyal following to its conservative personalities. Lately, CNN has also trailed left-leaning MSNBC in prime-time ratings.

In 2014, Fox News drew an average of 1.7 million prime-time viewers, to 600,000 for MSNBC and 500,000 for CNN, according to figures compiled by the Pew Research Center. But Pew also noted that CNN's estimated $1.1 billion in revenue last year was more than double what MSNBC brought in, while Fox generated $2 billion.

Zucker, the former head of NBC Universal, arrived in late 2012 to lead CNN out of its ratings struggles. Among his more controversial moves was to launch a new travel show for chef Anthony Bourdain, not exactly the hard news CNN was built on.

“The problem with news and the problem with building an audience around news on a 24-hour station is people want to turn on the TV when they know something is happening,” said Gabriel Kahn, a journalism professor at the University of Southern California. “It’s difficult to sell ads against that. It’s difficult to build a loyal audience.”

Parent company Turner Broadcasting remains under financial pressures and announced last year that it was cutting 10 percent of its staff, a trim that hit Atlanta hard. And CNN seems to be de-emphasizing its Atlanta roots, even as it says it remains committed to its headquarters.

“Most of their shows are out of New York or D.C. now,” said Mitch Leff, the president of an Atlanta public relations firm and a former Turner employee. “There’s not a whole lot out of Atlanta compared to what there was 10 years ago.”

With cable news viewership down overall, many resources are shifting online, especially as CNN adds staff to cover the presidential campaign.

It hired away several well-known Washington journalists from outlets such as Politico, The Washington Post and The Wall Street Journal. They are part of an aggressive digital push that goes beyond its cable news rivals and extends to youth-oriented platforms such as Snapchat.

For the month of July, CNN.com boasted 194 million video streams, 19 million unique viewers and 1.3 billion minutes of video consumed, tops among news sites. Its closest competitors there were not Fox News and MSNBC, but Yahoo News and Buzzfeed.

Feist said the network hired 45 people in the past year to work on CNNPolitics.com and is about done staffing up for 2016.

“Without a doubt, our online audience is something we have invested heavily in this cycle,” he said. “Clearly, it’s paying off.”