5 things to watch for in the second Republican debate

The latest CNN poll finds that Carson is the best-liked candidate in the entire field with a whopping 76 percent of Republican voters saying they're either "enthusiastic" or "satisfied" with his candidacy. Perhaps it's his lack of political experience.

3. Does Carly Fiorina have the most to gain?

The former CEO of Hewlett-Packard comes in with high expectations, sharing the stage with top contenders after Republican voters declared her the clear winner at the "kids table" debate on Aug. 6. With the two other political neophytes pulling a whopping 50 percent of the field in the new CBS/NYT poll, Fiorina, who landed 4 percent, may have an opportunity to ride the anti-establishment wave. Her debate instinct to go for the jugular has been a topic of discussion, and she has defended herself against Trump's attacks on her appearance—"I am proud of every year and every wrinkle," she said recently. A successful showdown with Trump, should she choose to go there, could do wonders for her.

4. Who will endorse a government shutdown?

The debate will be an opportunity for Texas Sen. Ted Cruz, who has been inching upward in the polls, to channel the conservative fury at Planned Parenthood and elevate a battle to defund the group at risk of a government shutdown on Oct. 1. Cruz played a leading role spurring the 2013 shutdown over the Patient Protection and Affordable Care Act (PPACA), and he became a conservative hero even though it failed—the base blamed congressional Republican leaders and held up Cruz as a fighter. Now a presidential candidate, Cruz is seeking to reignite some of that PPACA shutdown mojo as he makes a strong play for evangelical Christian voters.

How will other candidates respond? Florida Sen. Marco Rubio and Kentucky Sen. Rand Paul have been less enthused about shutdowns, but they won't want to risk being painted on the wrong side of the base. Wisconsin Governor Scott Walker, seeking to recover from his recent collapse in the polls, has echoed Cruz's criticism of GOP leaders as weak-kneed. Non-congressional candidates have little to lose because they won't have to cast a vote. The result could be a presidential field egging on a shutdown.

5. Can establishment candidates win hearts and minds?

The Trump/Carson surges have stunned establishment favorites—Bush, Rubio and Walker—and threaten to upend a decades-long trend of Republican voters nominating a candidate popular with donors and other party elites. Expect Bush to play up his experience as Florida governor in delivering for conservatives. Expect Rubio to call for a new leader in a "new American century." Expect Walker to tout his success at crushing public sector unions in Wisconsin. Expect Ohio Gov. John Kasich, who has leaped ahead of Bush in recent polls in New Hampshire (a key state for Jeb), to try to establish himself as a strong candidate in the minds of party elites and more moderate GOP voters. Expect New Jersey Gov. Chris Christie to look for some way, any way to revive his white knight status with bigwigs.

Ultimately, though, can these appeals win over Republican voters who are disgusted with politicians and determined to punish them? Or will the 2016 primary turn Republican politics on its head by busting a longstanding trend? Expect the second debate, and the fallout to provide some clues as to what's going on in their minds.