Arianna Huffington is guest-hosting Rachel Maddow's show on MSNBC tonight, and the lineup looks impressively ambitious: Google CEO Eric Schmidt, HBO talk-show host Bill Maher, stat-whiz Nate Silver and Cory Booker, the Newark mayor to whom the internet publisher was once rumored romantically linked (absurdly, her staff thought). The high-profile lefty gig is an appropriate laurel for an ambitious woman whose left-leaning site produced landmark coverage and gangbusters traffic amid the 2008 election. But as former Huffington Post staff can attest (and have), television appearances also mean a frenzy of last-minute research for editors like Roy Sekoff or Colin Sterling who prepare Huffington's talking points. With an entire, hourlong show to host, rather than a brief guest appearance, it would be reasonable for staff to fear another of the screaming, teary emotional breakdowns described to us by several former HuffPo staffers.

Among the tips that poured in after we started really asking questions about Huffington last month, in the wake of a New Yorker profile of the onetime socialite, was one claiming Huffington "had a breakdown (like bat-shit crazy person breakdown) in front of one male staffer who was working on Right Is Wrong," Huffington's recent political book. Another ex-HuffPo staffer subsequently confirmed the account to us, saying the staffer in question was shaken up, and pointing to Republican strategist Ed Rollins' book for more examples (it's on order!).

This second staffer said many HuffPo staffers are, at some point in their employey, witness to such breakdowns: Yelling, followed by an enraged denunciation of the person's skills and/or value as an employee and/or as a person, then tears and, perhaps, a later attempt at reconciliation.

Several other ex-HuffPo insiders said that general description of the quality and quantity of Huffington's rages met with their experience. "The breakdowns entail screaming and crying for a drawn out period of time," one said. Another:

Breakdowns are frequent... Although it's not so much crying as this wail-y, near-crying, cracked voice she employs when she is quite literally shaking with rage. When you hear that voice you know you're well past the point of no return.

Some breakdowns arose during Huffington's work on books, serious and stressful extracurricular projects that in many ways resembl, say, hosting a top-rated MSNBC show for a night. From that perspective, staffers have good reason to walk on eggshells (when not running personal errands) in the runnup to the Rachel Maddow Show gig tonight. It can't help Huffington's mood that she'll be working for a network where she was once reportedly banned for attacking Meet The Press host Tim Russert, the longtime Huffington enemy who has only grown more revered since his passing.

On the other hand, multiple former staff said Huffington's fits were often set off by trivial matters, disproportionately including minor issues with cars and drivers.

Take the subway, Arianna, for everyone's sake! Your show sounds fun.

If anyone knows how Huffington is doing, today, this week or at some point in her long past, we'd love to hear from you.

Prior Huffington coverage: The Huffington Posts