High stakes and egos will converge Thursday as Hillary Clinton testifies at the latest hearing of the House Select Committee on Benghazi.

If you love politics, tune in, because it's sure to be chock full of narratives.

That's because plenty of those present -- and hardly just Clinton -- come before the cameras with something to prove. Here's a glimpse at what some of their motivations are: 

Hillary Clinton: Maintain momentum and avoid pitfalls

The political winds are at the back of the Democratic front-runner going into Thursday, and Clinton would like to keep it that way.

Yes, she'll have to face persistent questions about why she used a private e-mail server exclusively while secretary of state (the Benghazi committee's inquiries into her e-mails brought her reliance on the server to light). But just in time, Clinton was handed a political gift when House Majority Leader Kevin McCarthy (R-Calif.) and another Republican said what many Clinton backers suspected: That this ninth investigation into the September 2012 attacks has political aims.  

To do that, Clinton will have to keep her cool and try to appear above the fray. It's going to be a physical and mental feat; she's got to stretch her confident, relaxed, authoritative two-hour Oct. 13 debate performance -- amid mostly friendly fire -- into what could be many hours sparring with people who don't want her to succeed. She'll also need a little luck to hope a rotating cast of Republicans get tired (and maybe cranky) well before she does.

House Republicans: Prove the investigation's viability

It took just one comment from McCarthy to throw into question the true purpose of this Benghazi investigation: "Everybody thought Hillary Clinton was unbeatable, right? But we put together a Benghazi special committee, a select committee. What are her numbers today? They're dropping."

Another Republican, Rep. Richard Hanna (N.Y.), soon echoed McCarthy's words, and a GOP staffer who was fired from the committee has made similar accusations. 

Now House Republicans, who promised to investigate Benghazi "to ensure the American people have the truth about the terrorist attack on our consulate that killed four of our countrymen" -- to use Speaker John Boehner's (R-Ohio) words -- have a PR problem on their hands.

And polling reflects that. According to a new Washington Post-ABC News poll, more than half of Americans (53 percent) think Republicans investigating Benghazi are trying to damage Clinton politically. Those numbers do break down along party lines, but independents side mostly with Democrats:

To change Americans' minds, committee head Rep. Trey Gowdy (R-S.C.) is asking -- pleading, really -- for his Republican colleagues to stick to the facts Thursday and avoid politics.

But unfortunately for GOP leaders and presidential hopefuls, the more political Thursday's hearing gets, the more it confirms the unfortunate narrative they themselves are responsible for.

Rep. Trey Gowdy: Mind his bright political future

Speaking of Gowdy, Rep. Paul Ryan's (R-Wis.) potential anointment as speaker isn't sewn up yet. And some are clamoring for Gowdy to step up. He was already a contender for the second-most powerful position, House majority leader, when Rep. Kevin McCarthy (R-Calif.) briefly ran for speaker. Gowdy has said he's not interested, but clearly his future is bright.

But first Gowdy has got to prove he can handle this investigation. As described above, things haven't gone his way lately; he recently told Politico "these have been among the worst weeks of my life." Gowdy has got to get everything back on track Thursday by doing nothing short of winning the battle between him and Clinton and keeping things civil.

Half a dozen other Republicans: Keep climbing the ladder

Gowdy won't be the only Republican in Thursday's hearing angling for a promotion. Some of the six other Republicans who sit on the panel could be interested in leadership positions that, if recent history is any guide, could be available sooner than later.

They include House Freedom Caucus member Rep. Jim Jordan (Ohio), as well as Mike Pompeo (Kan.), who has flirted with running for speaker, and Peter Roskam (Ill.), who has served as chief deputy whip. These members were not chosen for the committee because they are back-benchers. Many of them have significant heft.

Rep. Elijah Cummings: Keep his Senate options open

Democrats on the committee don't plan to be wet logs Thursday. According to The Washington Post's Karen DeYoung, they plan to ask questions designed to give Clinton more time to get her side across.

One in particular -- Rep. Elijah E. Cummings (D-Md.) -- has ample experience in confronting heated Republican investigations. He's both the ranking member on this Benghazi investigation and on the often-very-political House Oversight and Government Reform Committee (remember Cecile Richards' recent testimony there on Planned Parenthood?)

Cummings is well-respected in Democratic circles, and he also happens to be contemplating a Senate run for the open seat in Maryland. (Longtime Democratic Sen. Barbara A. Mikulski is retiring). A new Washington Post poll this week suggests Cummings would instantly be the front-runner in that crowded primary, and how he performs on Thursday's big stage will undoubtedly be of interest.

In short, most people in that room have at least some reason to be on their game. Stay tuned.