U.S. Republican presidential candidate Donald Trump waves to the crowd as he leaves a campaign rally at the University of Iowa in Iowa City, Iowa, January 26, 2016. REUTERS/Scott Morgan

Donald Trump has figured out how to make the buzz around a Thursday night debate of Republican presidential candidates all about him: by vowing to skip it.

But the billionaire’s move, days before Iowa holds the first nominating contest of the 2016 election, is a gamble.

After Trump said he was boycotting the Fox News-sponsored debate because of a feud with anchor Megyn Kelly, rivals accused him of being too afraid to face them on stage. While some of Trump’s fans were supportive of his decision, several undecided voters said they were unimpressed.

“I was on Trump’s doorstep until this whole thing happened. I was disappointed,” said Bryan Moon of West Des Moines, Iowa, who was attending an event for Republican Marco Rubio. “If this is how he’s going to act, that ‘I’m taking my ball and going home,’ then that is just not going to work.”

Voter Jill Ruby, another West Des Moines resident at the Rubio event, was equally put out by Trump’s decision.

“Are you kidding me, a reporter ticked him off?” she said. “He’s a coward. I think it will come back and bite him. That’s not how a president acts, you don’t just run away.”

Although Trump leads polls of Iowa Republicans over U.S. Senator Ted Cruz of Texas, many voters remain undecided and are looking to the debate to aid their decision-making.

“It gives people a reason to be disappointed in him and take a look at the other candidates,” said Republican strategist Charlie Black. “It could hurt him with people who might be undecided.”

Trump planned to hold a fundraiser for veterans at Drake University in Des Moines at the same time as the Fox debate, according to an invitation circulated by his campaign.

Early on Thursday, Trump tweeted: “Wow, two candidates called last night and said they want to go to my event tonight at Drake University.” He did not elaborate and there was no word from other candidates about plans to join the front-runner.

Trump’s rivals view the debate, which begins at 9 p.m. EST (0200 GMT), as a chance to get their own messages across without having to compete with Trump’s bomb-throwing rhetoric.

“It gives us more time at the microphone and more time to talk about answers to substantive issues that Iowa voters are demanding right now,” said David Kochel, a senior adviser to Republican candidate Jeb Bush.

On the down side, the number of people who tune in could be lower without Trump at center stage.

“It is undeniable that what he’s doing is denying his opponents a large audience as they make their final arguments to Iowa voters,” said Eric Fehrnstrom, a Republican strategist who advised the party’s 2012 nominee, Mitt Romney.

Trump’s decision to stage a benefit event to help military veterans instead of participating in the debate was welcomed by some supporters.

Pat Wiltfang, 59, of Grinnell, Iowa, a lifelong Republican who had watched all the previous debates, said she was pleased with Trump’s decision and would gladly skip this one.

“That’s a great move,” said Wiltfang, who plans to caucus for Trump. “All it is is just everyone trying to attack.”

While it might be tempting for Trump’s rivals to use the debate to criticize him aggressively, some Republican analysts are cautioning against a scorched-earth approach.

“It’s delicate for the candidates because you have to pull back from attacking a man who is not there,” said Ari Fleischer, who was White House press secretary for President George W. Bush. “It will be OK to make a passing reference or two, the fact that he’s not there. But if you try to beat him up, it won’t play well because he’s not there to defend himself.”

But campaigning on Wednesday in West Des Moines, Cruz mocked Trump for skipping the debate, calling him a “fragile soul.” He renewed his offer to Trump to debate him one-on-one Saturday.

“It’s not that he’s afraid of me,” Cruz told the crowd. “He’s afraid of you. He doesn’t want to answer questions from the men and women of Iowa about how his record doesn’t match what he’s selling.”

No one would be shocked if Trump changed his mind about the debate.

“I’ve got a $20 bet he’ll show up,” rival Jeb Bush said. Why? “Because it’s in his interests.”