DES MOINES — Donald Trump has taken plenty of gambles on real estate and casinos. In politics, his wager on a brash, attacking style has paid off. Now, just days before the Iowa caucus, he’s betting that he’s bigger than Fox News.

In refusing to attend Thursday’s Republican presidential primary debate in Des Moines — because Fox did not accede to his demand that anchor Megyn Kelly be removed as moderator — Trump once again grabbed the media spotlight and proved his potency as an unpredictable and polarizing force.

At the same time, he risks marginalizing himself by looking as though he is shying away from a fight, refusing to publicly debate his GOP rivals and heading for the sidelines because he didn’t get his way. The front-runner’s absence from center stage could give Senator Ted Cruz, who is running second in Iowa, the opportunity to make a stronger case in the final moments before votes are cast Monday.

After his announcement about skipping the debate Tuesday night, his opponents on Wednesday mocked him. Cruz accused him of being “afraid’’ of Kelly and of avoiding a “job interview’’ with Iowa voters. Conservative firebrand Rush Limbaugh defended him. Iowa supporters stood by him. Even some neutral observers applauded.

“I think it was a brilliant move,’’ said Jeff Jorgensen, chairman of the Pottawattamie County Republican Party, who is not supporting any candidate. “Here’s the thing: What’s everybody talking about? Donald Trump not showing up. He’s now part of the debate by not even showing up.’’

Trump was planning his own event in Des Moines to coincide with the debate Thursday, drawing some media attention away from the main stage and raising money for wounded veterans.

The reality TV star and real estate mogul’s political rise has been fueled by media coverage reacting to his controversial claims, personal attacks on his opponents, and highly charged attacks on Muslim and Mexican immigrants. The GOP debates have won huge ratings for the networks, and big bounces in the polls for Trump.

One of the ironies is that Fox News helped stoke the Tea Party revolution in the Republican Party, beginning in 2010. Now, one of the biggest figures spawned by that GOP civil war is turning on the network.

Trump has continued to use the network to reach conservative voters. Just before announcing his debate boycott, he appeared on the network with anchor Bret Baier. Wednesday night he was scheduled to appear on commentator Bill O’Reilly’s show.

By skipping the debate, Trump will also avoid any harsh questions about some of his past positions — particularly those that favored abortion rights — that are out of step with Iowa’s conservative caucus-goers.

Core Trump supporters disputed the idea that their candidate was shying from a debate with Cruz and the other candidates.

“He knows when to walk away from a bad deal. And you know what? This was a bad deal,’’ said Cheryl Tancreti, a Trump volunteer who hasn’t caucused in two decades but has grown excited about Trump.

“Fox doesn’t treat him fairly at all,’’ she added. “I’m not even going to turn it on or have it recorded, nothing.’’

Julie Fredrickson, who recently stood outside in the snow to see a Trump rally, is a regular Fox viewer who is siding with her candidate.

“I like Megyn Kelly. But she was kind of rude to him in that first debate,’’ she said. “Sometimes women just go a little too far with this equality and all the stuff.’’

During the first GOP debate, in August, Kelly pressed Trump on whether he had the “temperament’’ to be president.

“You’ve called women you don’t like ‘fat pigs,’ ‘dogs,’ ‘slobs,’ and ‘disgusting animals,’’ she told him.

The next day, Trump said on CNN that Kelly had “blood coming out of her wherever,’’ a remark that many took as a crude reference to her menstrual cycle. Fox News’s chief executive, Roger Ailes, stuck by Kelly and called Trump to complain about his behavior.

For about a week in September, Trump boycotted all Fox shows, and he has continued complaining about Kelly on Twitter. Over the last several days, with Kelly again a co-moderator, Trump began suggesting he would boycott the debate, asking his 5.8 million Twitter followers whether he should.

Fox executives would not relent on Kelly, but the network on Tuesday released a statement mocking Trump — a bizarre move for a news organization that gave Trump an opening to question its objectivity.

“We learned from a secret back channel that the Ayatollah and Putin both intend to treat Donald Trump unfairly when they meet with him if he becomes president,’’ the statement read. “A nefarious source tells us that Trump has his own secret plan to replace the Cabinet with his Twitter followers to see if he should even go to those meetings.’’

Trump continued the feud on Wednesday morning.

“I refuse to call Megyn Kelly a bimbo, because that would not be politically correct,’’ he wrote on Twitter. “Instead I will only call her a lightweight reporter!’’

Cruz’s campaign got the rights to a website — MakeTrumpDebateAgain.com — and began selling hats with the phrase, a play on Trump’s campaign slogan “Make America Great Again.’’ He also challenged Trump to a one-on-one debate.

Trump, who has been raising questions about whether Cruz’s birth in Canada hinders him from seeking the presidency, responded, “Can we do it in Canada?’’

Senator Marco Rubio pleaded for a more sober discussion.

“I think this whole thing between Donald and Ted Cruz is theatrics and an interesting sideshow,’’ he said. “But this is about the future of America.’’

Matt Viser can be reached at matt.viser@globe.com.