Why tonight's GOP debate might make or break campaigns

What's at stake for all but one of the 16 candidates set to participate in the GOP's second televised debate Wednesday evening?

Money, and with it, the survival of any given candidacy.

A weak performance Wednesday night could cause a candidate's fundraising to dry up, and with it, his or her campaign. A strong performance, on the other hand, could energize fundraising before a deadline at the end of this month.

"There is a great deal at stake in tonight's debate," says David McLennan, a visiting professor of political science at Meredith College in Raleigh, N.C. "The field will continue to contract with those that do not stand out in the debate running the risk of seeing their funds dry up, as Rick Perry faced after the Fox News debate. When the money stops, so does the campaign."

"This is psychological warfare," as Republican strategist Ford O'Connell put it. "[Candidates] need to do well to make sure others don't get the money.... No one wants to be the next Rick Perry."

The hours immediately following Wednesday night's debate are particularly important for raising campaign cash. That's because fundraisers tend to tap big donors when emotions are high, like immediately after a strong debate performance. “This is the most leverage you have,” an unnamed GOP super PAC fundraiser told Politico.

Tonight's debate also sets off a two-week-long mad dash for cash ahead of the quarterly fundraising deadline on Sept. 30. That means candidates, especially those at the bottom of the pack, are under enormous pressure to attract enough attention to stay afloat and keep the funds flowing.

Of course, each candidate faces a different challenge, or opportunity, with Wednesday night's debate.

Former Florida Gov. Jeb Bush needs to do well enough "to pacify jittery donors," says Mr. O'Connell. "They're not sure he can come out on top. His supporters are looking at others like [Ohio Gov.] John Kasich and [Florida Sen.] Marco Rubio. Bush needs to make sure others don't get the money."

And while retired neurosurgeon Ben Carson's recent rise has attracted small dollar donors from thousands of grassroots supporters, he needs to attract and impress bigger donors in tonight's debate.

"The financial stakes are probably highest for lesser known candidates," says Tim Vercellotti, professor of political science and director of the Western New England University Polling Institute at Western New England University in Springfield, Mass. "Would-be donors need to see some evidence of viability before they will get behind a candidate who is still relatively unknown to voters."

That goes for the Rick Santorums, Bobby Jindals, and George Patakis of the race.

"The stakes also may be significant for candidates who entered the race amid high expectations from news media and political powerbrokers, only to perform below those expectations," adds Professor Vercellotti. "Scott Walker is a good example. If he does not do well tonight, his individual donations could suffer."

The one exception? Donald Trump. The billionaire casino mogul doesn't need to do well to get fundraising – he's bankrolling his own campaign. But he does need to do well to stay on top of the polls.

The other 15 candidates unequipped to self-finance their campaigns – all of whom know there's not enough campaign cash to go around such a large field – are banking on making a splash at Wednesday night's debate.