On Wednesday night, eight Republican presidential candidates gathered in Milwaukee for the first GOP primary debate.

There was a lot on the line for each of them.

But there was also an enormous amount at stake for the news organization that hosted the debate.

Fox News.

Consider the cross-currents that the two Fox moderators, Martha McCallum and Brett Baer, had to deal with.

First, there was Trump, who refused to participate and lashed out at Fox and its talent, including Baer on social media.

Then there was Tucker Carlson, McCallum and Baer's former star colleague, who is in messy litigation with the network, and who nabbed Trump for himself and counterprogrammed the evening with an interview that aired simultaneously with the Fox debate.

Then there was Rupert Murdoch hovering in the background.

In the days before the debate, there were new reports that the man who runs Fox, McCallum and Baer's boss, has his own strong feelings about who the GOP nominee should be.

If that isn't enough on the eve of the debate, several candidates who didn't qualify to be on stage threatened to sue.

Add to that the challenges of being the ones asking the uncomfortable questions in that arena on Wednesday.

The candidates are primed to pounce on you if it serves their political interests. The boisterous crowd of partisans could turn on you at any moment.

So what was it like behind the scenes at the Fox News debate? How did the host prepare, including for a possible last minute appearance by Trump?

What did they think of the highly caffeinated Mike Pence interrupting them at every turn?

What was the deal with DeSantis and Christie during that one hand-raising moment?

And whose idea was that UFO question anyway?

We're going to ask Martha and Brett those questions and a lot more as they bring us inside what is perhaps the most important event of the GOP primary so far.

I'm Ryan Liza and this is Playbook Deep Dive.

From your perspective sitting there, it's obviously so much different than anyone watching it at home.

When you look back at that intensive two hours, what are the biggest moments that stand out?

When you were sitting there, you were like, oh boy, this is a moment.

One big one for each of you just to start off. Go ahead, Martha.

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