Editor’s Note: Watch the CNN debate at the Ronald Reagan Presidential Library on Wednesday Sept. 16 at 6 and 8 p.m ET, and get the latest news from CNN Politics

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No one has more on the line in Wednesday night’s Republican presidential debate than Jeb Bush.

The former Florida governor with one of the most recognizable names in politics and $100 million in the bank is facing one of the most crucial moments of his political career at the CNN debate held at the Reagan Library.

In the unpredictable GOP race for president, Bush is struggling to regain his footing in the midst of Hurricane Trump. He first tried to ignore the bellicose billionaire before changing course and punching back hard. He has released detailed tax and immigration reform plans to show he is about substance, not style. He has kept a rigorous pace on the campaign trail, squeezing in Monday meetings with tech leaders in Seattle before heading off to Nevada and Michigan post-debate.

CNN Republican presidential debate

The payoff for all that hard work? A steady slide to the middle of the pack that is giving Bush donors the jitters and an opening to rivals like Ben Carson and Ohio Gov. John Kasich to overtake him in key early-voting states.

Here’s a look at some of the hurdles Bush and other GOP presidential contenders face going into debate night.

Bush

The former Florida governor’s initial assets – money, connections and political experience – have made his downward trajectory all the more striking as he wrestles to regain control of the campaign narrative.

“These debates are increasingly life-and-death moments for candidates who started out as the presumptive frontrunners but have fallen to low single digits,” said Republican strategist Steve Schmidt, who listed Bush, Scott Walker and Marco Rubio in that category. “The first step to securing the nomination, is taking control of your destiny, completely within the process. At this point in 1999, George W. Bush had accomplished that. At this moment in time, Donald Trump has accomplished that,” said Schmidt, a former aide to the elder Bush who advised John McCain in 2008.

“None of these candidates have any ability to control their own destiny any longer—their capacity to rise from 3-, 4-, 5-, 6% is fundamentally about Donald Trump losing his grip,” Schmidt said. “No other candidate, with the possible exception of Ben Carson, is within reach to beat Trump. Only Trump can beat Trump.”

Bush is making a noticeable effort to retake control over his campaign narrative. He’s dropped his hands-off approach to Trump in favor of direct confrontation. He’s letting his personality show more often by, for instance, unbuttoning his shirt over the weekend to reveal a shirt with the 1984 campaign logo of Ronald Reagan and his father.

READ: Jeb Bush speaks Spanish in video celebrating Hispanics

And he released a campaign video on Monday in which he speaks Spanish – defying Trump’s calls that Bush only speak English on the campaign trail. The video also includes a rare appearance from Bush’s wife, Columba, who is an immigrant from Mexico.

“I have lived over half my life here,” she says in English in the video. “We all have the same interests, the same feelings.”

Still, the moves aren’t helping Bush much in the polls. A Monmouth University poll released on Monday found that in New Hampshire, Bush has slipped from second place into a tie for fifth with Carly Fiorina at 7%.

Trump

Given his defiance of the normal rules of political gravity, it’s become difficult to predict the kind of error that would stunt Trump’s momentum.