The moderators for the three upcoming presidential debates between Democrat Hillary Clinton and Republican Donald Trump should have been set by now.

But the selection process isn’t following routine, like so much in the 2016 run for the White House.

The Commission on Presidential Debates has delayed choosing the moderators until after Labor Day, CNN has reported, in part because of the “unprecedented challenge” the panel faces in selecting hosts that are acceptable to both campaigns. The plan originally was to announce a set of hosts by late August — the first debate is Sept. 26 at Hofstra University.

The commission is being cautious especially to avoid attacks from Trump, who frequently criticized moderators and formats during the Republican primaries and even skipped one debate, CNN said. The nonpartisan commission didn’t immediately return a call to comment.

The delay perhaps increases the pressure by “calling attention to the fact that the people who are deliberating are having some sort of problem,” said Paul Levinson, a Fordham University communications professor and author of “New New Media.”

“The delay only makes everyone more uncomfortable and more anxious,” he said. “They’ll probably never tell us the real reason. But it probably has more to do with Trump than Clinton . . . because everything that Trump’s been doing has been about blowing up the process.”

advertisement | advertise on newsday

Levinson said it’s unlikely there will be a debate scenario that satisfies both sides. Given the polarizing personalities of the candidates, the selection of moderators might be more important in this election than in recent ones. He said the commission needs to select “someone to ask tough questions, who won’t be talked over or interrupted.”

Knowing the moderators is a crucial part of “creating ‘game day’ atmosphere as part of your preparation,” said Kevin Madden, spokesman for Republican Mitt Romney’s 2012 presidential campaign. It’s part of anticipating questions from panelists and attacks from your opponents. Raising questions about the format is part of it, too.

“I think he thinks that kind of commotion works in his favor,” Madden said, referring to Trump. “He likes to be disruptive to the other campaigns. He’s more of an instinct player so he probably doesn’t need as much preparation. She’s much more studious, so not knowing is probably more disruptive to her.”

However, Clinton has far more experience at one-on-one debates than Trump, Madden added.

Trump signaled his potential to object when he told Time magazine last week: “I will absolutely do three debates. I want to debate very badly. But I have to see the conditions.”

Along with the debate in Hempstead, the commission has scheduled faceoffs Oct. 9 at Washington University in St. Louis, and Oct. 19 at University of Nevada in Las Vegas. The lone vice-presidential debate is slated for Oct. 4 at Longwood University in Farmville, Virginia.

“The fact that Trump would want to enter into a debate about debates is not surprising,” said Marist College pollster Lee Miringoff. “But because he’s trailing [in the polls], ultimately, Trump needs this debate whether he wants to or not.”

Jockeying over selection and format is nothing new, noted University of Virginia political scientist Larry Sabato, a longtime chronicler of presidential and congressional elections. Many political experts noted that CNN’s Candy Crowley drew harsh criticism from Republicans in 2012; PBS’ Gwen Ifill too in 2008. But the commission must act soon because it’s getting “awfully late,” he said.

“I’ve done debates for the Senate and House and there’s a lot of work in it,” Sabato said. “You don’t just sit down for an hour and then pop off questions — unless that’s what they want.”