Jeb Bush's father, mother, brother, and legions of big donors gathered in Houston this week and fretted over what they see as the biggest threat to the Jeb campaign: Donald Trump. But while Trump is a threat to the donor class as a whole, the real threat to Bush is Marco Rubio. And he's running out of time to figure that out and do something about it.

Eli Stokols's account of the summit offers a powerful picture of a campaign that has enormous strengths but is also floundering and dangerously close to losing the support of its key backers. Bush's campaign is suddenly facing fundraising woes and finds itself slashing staff salaries and other expenses. If that leads to departures, defections, or even just anonymous complaints in the media, it could further fuel donor doubts.

A vast family network rallied around him as soon as he threw his hat in the ring, but there's more to politics than personal loyalty, and Bush has a huge problem in the form of former protégé Marco Rubio, who simply looks like a more skilled politician at this point. Bush and Rubio are very similar ideologically, so a trickle of support flowing from the former to the latter could turn into a flood at a moment's notice.

A helping hand from his family can staunch the bleeding temporarily, but ultimately Jeb needs another chance to prove that he's a competent politician. This week's Republican debate in Colorado is an ideal opportunity to do that. And it might be his last.

Trump is not the problem

Jeb and the Bush circle flatter themselves by positing that Donald Trump is the main reason for his struggles. As Stokols put it, channeling the Bush supporters he spoke to in Houston, people worry that "a family held in such high esteem by generations of Republicans no longer represents the party it once led."

But this is a revisionist take on the Jeb phenomenon.

He didn't score his unprecedented fundraising haul because the donor class thought he was perfectly in line with the prevailing mood of tea parties. They wrote giant checks to the Right to Rise PAC because Jeb was supposed to take the party in a sunnier, more optimistic, more Latino-friendly direction while simultaneously delivering the tax cuts, deregulation, and bailouts that rich donors crave.

Even before Trump's rise, Jeb was supposed to be the antidote to Trumpism, just as George W. Bush successfully rebranded the GOP as all about "compassionate" conservatism even while keeping the tax cuts flowing.

Bush's problem isn't so much that the party is moving in a Trumpish direction as it is that he is doing a terrible job of standing up for the non-Trump values.

What candidate is Jeb World most obsessed with? Marco Rubio, singled out more than Trump in slideshow for donors pic.twitter.com/tbsODECeob — Marc Caputo (@MarcACaputo) October 26, 2015

For my money, the most important moment of the 2016 GOP primary was this exchange in the CNN debate where Donald Trump criticized Jeb Bush for speaking Spanish on the campaign trail. You can see why this works as a populist-nationalist slam on Bush, but Bush ought to have a strong rejoinder — Republicans who want to win really do, after all, want a nominee who can speak to voters in Spanish. Instead, Bush muffed the answer only to be followed by Rubio delivering a defense that was about a million times better.

Rubio's brilliant answer, Jeb's whiff

"If a high school kid asks me a question in Spanish," Bush said before launching into an off-topic digression in Spanish, "and they ask me a question in Spanish, I'm going to show respect and answer them in Spanish."

On the one hand, this is uninspiring. On the other hand, it reflects immigration skeptics' deepest fears about the direction of the country. Is America becoming the sort of place where a person who speaks only English — i.e., most Americans — will be considered rude?

Rubio's answer, by contrast, hit all the right notes. He started out with an affirmation of the principle that in America, everyone should learn English. But then he spoke of his grandfather, a refugee from communist Cuba who "loved Ronald Reagan" and taught him that America was the greatest country on Earth, "but he taught me that in Spanish." Rubio explained that he believes that "free enterprise and limited government" are the best path forward for the country, and that he wants to carry that message forward to Spanish speakers in Spanish rather than leaving it "in the hands of a Univision translator."

This isn't going to persuade a hardcore racist, obviously. But it's smart politics — not challenging the Spanish-averse on values but simply putting forward the idea that as a practical matter Rubio's fluency should be seen as a strength. Bush would have had to tweak the biographical details, but he could have made the basic argument. He just didn't. Because time and again he's seemed like a hesitant and slightly dull politician.

A last chance at a turnaround

This week's debate is Bush's last, best chance to turn that impression around. He still has an enormous set of strengths related to the vast potential of his personal and family network. But he desperately needs to show some forward momentum.

A good zinger or two. A nice riff. Something. Anything.

There are real pros to being the establishment favorite, even in the context of a primary that is being roiled by anti-establishment forces. But to be the establishment candidate, you need to look like the candidate the establishment should be backing. So far, that's looked like Rubio or even John Kasich or, arguably, Carly Fiorina. Bush should be the guy in this race who shows the most professionalism and polish. But unless he can start showing those qualities soon, he won't be in the race for long. After all, if you live by the elite donor network, you also die by the elite donor network, and it's clear that elites are running out of patience with the latest Bush.