In split-screen America, the presidential race that could have been

Donald Trump, with reality-show flair, sliced American politics into a split screen on Thursday night.

On one screen, Trump stood before a cheering crowd in a debate-night stage built-for-one and shouted, "This is like the Academy Awards!"

On the other, standing before a panel of tough questioners, seven candidates fought each other for airtime in a GOP presidential debate sapped of its biggest draw.

The Trump Show, an alternative event spawned by the Republican front-runner's spat with Fox News and carried live on the cable network's rival, CNN, arrived in Iowa with all the buildup of a made-for-TV spectacle: the breathless wait for the arrival of his jet, the will-he-or-won't-he speculation, the uncertainty of it all.

Fox News - playing by the conventional rules of television journalism - would have to share the spotlight of a nation with a suddenly and sharply divided attention span.

The night belonged to Trump.

The real estate mogul-turned-politician made sure of that with days of hints that he would skip the Fox debate, a supposedly crucial showdown just days before the Iowa caucuses.

An hour-and-a-half before Fox's official debate, the conservative network was airing a low-profile "undercard" debate of four struggling candidates. CNN was offering views of idling SUVs outside a plane with the word TRUMP on the fuselage. Fox had Mike Huckabee, the former Arkansas governor, talking about losing jobs to Mexico; CNN had excitement. Trump was on the ground, and everyone wanted to know whether he would change his mind at the last minute and head to the Fox debate anyway. Trump was the story.

Once the Fox debate began, even Trump's foil, the star Fox anchor, Megyn Kelly, acknowledged as much in her opening question to the Republican candidates arrayed, somewhat awkwardly, in front of her: "Let's address the elephant NOT in the room," she said to Trump's chief rival, Texas Sen. Ted Cruz.

Given that opening, Cruz declared, "I'm a maniac," and went on to say the others on the stage were "fat and ugly."

"Now that we've got the Donald Trump portion of the way . . . " he deadpanned.

What was missing as the crowd laughed at one side of America's split-screen on Fox was any sign of a real-time Trump on CNN or any of the Internet sites hungrily streaming his event. About six minutes in, Marco Rubio, the Republican senator from Florida, tried to diminish Trump, quipping that he was "the greatest show on earth."

CNN could only roll tape. "Awaiting Trump event."

For a while on Fox, it started to look like what the Republican race might have been had Trump decided not to run after all. It was a glimpse at the GOP field that a year or two ago many thought would be strong and popular.

But then came the reality check.

Fifteen minutes into the Fox debate, as Ben Carson, the retired neurosurgeon, gave a rambling answer about finding "smart people" to solve problems, the other side of America's dueling screens lit up.

Trump, who had dragged out the suspense, came onstage to roars. On the live-streams, the red hats of his fans - the "Make America Great Again" headgear of choice - bobbed up and down on screen.

"Oh, wow," Trump said. "Wow!"

From then on, American voters had a choice: Trump, ticking through the names of rich friends who were donating millions to help wounded veterans, and then introducing his supermodel wife; or Cruz talking about military spending or jousting with Rubio over amendments to an immigration bill. Trump telling the audience that he hopes his pregnant daughter, on hand for the event, will have her baby in Iowa; or Jeb Bush - the former governor of Florida - complaining.

On one side, Rubio was talking about "armageddon"; on the other Trump talked about raising millions for veterans.

Rubio lamented to the Fox audience that the United States has "the smallest air force in our history," Trump was plugging his website.

At one point, Rubio warned about the dangers of terrorism. On the other screen, the billionaire who had once body-slammed wrestling impresario Vince McMahon on camera was bringing on stage Huckabee and another foundering candidate, Rick Santorum, the former Pennsylvania senator. The two stars of the earlier undercard had gone across town, at Trump's invitation, they said, to stand up for veterans.

Rubio was talking about threats to America. Trump was introducing two men who posed no threat - at least not to him.