You've seen him not lose his cool while 10 Republican presidential candidates onstage were all vying for the mic at the same time. So when (at last count) only four candidates show up to debate tonight in Detroit, serving as moderator should be a piece of cake for Dunwoody's own Bret Baier.

How hard can it be to deal with Trump when you’ve already played Tevye as a teenager?

That's right, Baier, now 45, had the lead role in "Fiddler on the Roof" way back when at Marist School in Atlanta. And that's not all we learned when we shadowed him as he prepared to moderate another hugely important Republican debate in South Carolina during the last presidential race. It turns out he'd also followed around a media bigwig as a school assignment back in the day: Then WSB sportscaster and now "NBA on TNT" star Ernie Johnson Jr. Later, when the then upstart Fox News hired him as an Atlanta-based reporter, his "bureau" was actually his apartment in Buckhead overlooking a once beloved, now defunct watering hole.

Baier, 45, will be joined by fellow moderators Megyn Kelly and Chris Wallace for tonight's debate on Fox News at 9 p.m. Before then, read our full story here about Baier, including the touching and stirring details of dealing with his newborn son's heart disease almost nine years ago.