Sparked by his narrow defeat in a Texas Senate race, Beto O’Rourke is scrambling the 2020 presidential primary field, freezing Democratic donors and potential campaign staffers in place as they await word of his plans.

Even prior to O’Rourke’s meteoric rise, many Democratic fundraisers had approached the large number of 2020 contenders with apprehension, fearful of committing early to one candidate. But the prospect of a presidential bid by O’Rourke, whose charismatic Senate candidacy captured the party’s imagination, has suddenly rewired the race.

O’Rourke — who raised a stunning $38 million in the third quarter of his race — is widely considered capable of raising millions of dollars quickly, according to interviews with multiple Democratic money bundlers and strategists, catapulting him into the upper echelons of the 2020 campaign.

Mikal Watts, a San Antonio-based lawyer and major Democratic money bundler, said several donors and political operatives in Iowa, after hearing from other potential candidates in recent days, have called to ask if O’Rourke is running, a sign of his impact in the first-in-the-nation caucus state.

“They’re not wanting to sign on to other presidential campaigns until they know whether Beto is going,” Watts said. “And if Beto is running, what good progressive Democrat wouldn’t want to work for Beto O’Rourke?”

He said, “I can tell you that there has not been this kind of level of electric excitement about a candidate since” Barack Obama ran in 2008.

O’Rourke raised more than $70 million in total in his bid to unseat Republican Sen. Ted Cruz, mostly from small donors in a race that captured national attention. Though he fell short — losing 51 percent to 48 percent — his closer-than-expected performance in the largest red state on the map was credited with lifting at least two Democrats to victory over House Republican incumbents.

“He’s game changing,” said Robert Wolf, an investment banker who helped raise Wall Street money for Obama in 2008 and 2012. “If he decides to run, he will be in the top five. You can’t deny the electricity and excitement around the guy.”

While other prominent Democrats, including Biden, Sanders and Sens. Kamala Harris (D-Calif.) and Elizabeth Warren (D-Mass.) have support networks of their own, Wolf said, “Beto comes out of [the midterm elections] saying, ‘Oh my God, if a guy can do well in Texas, he certainly can do well throughout the country as a Democrat.”

“I get the hype,” Wolf said. “I think there’s an incredible amount of excitement around Beto. A lot of people have comparisons around him and a Robert Kennedy or a Barack Obama. And the [Democratic] Party likes young, ambitious and aspirational.”

The ascent of O’Rourke, a three-term congressman from El Paso, reflects the volatility of a 2020 presidential primary that has flummoxed Democratic donors and activists for months. Many fundraisers who have exclusively supported a single candidate in previous years are expected to hedge their bets initially, spreading smaller amounts to several candidates.

One major Democratic bundler on the West Coast told POLITICO he is advising donors against throwing in with one candidate, saying, “It’s naivete, it’s political suicide to do that.”

O’Rourke is a major reason for donors' uncertainty, the bundler said, having “brought a whole bunch of new people off the sidelines.”

“That’s this cycle’s ‘Bernie army’ — it’s ‘Beto’s Army,’” he said, comparing O’Rourke’s Senate fundraising to the crush of small donors who propelled Sanders in his unsuccessful 2016 primary campaign.

“All the guy would have to do is send out an email to his fundraising base … and he raises $30 million,” the bundler said. “That has totally changed the landscape for the Tier 1 guys, because now Bernie and Warren, now they have competition. It completely changes the game if Beto runs. And he should run … He’s Barack Obama, but white.”

O’Rourke said before the midterm elections that he would not run for president, promising to serve six years in the Senate if elected. When asked at a CNN town hall if he would run for president if he did not win the Senate race, O’Rourke responded, “If I don’t win, we’re back in El Paso.”

But Democrats have not taken O’Rourke’s comments as ruling out a run.

“I think that’s a decision that he has to make as to whether or not he’s going to run for president,” Texas Democratic Party Chairman Gilberto Hinojosa said. “Everybody’s waiting to see what Beto’s going to do.”

Asked about a potential presidential run, O’Rourke told the website TMZ on Friday, “I haven’t made any decisions about anything.”

For Democratic strategists eager to advance a younger nominee contrasting with President Donald Trump, O’Rourke’s appeal rests on his perceived ability to bridge a gulf within the party — between Democratic contenders who are older but come with pre-existing donor networks, and Democrats who are younger but have not yet developed a substantial fundraising base. O’Rourke, at 46, has both.

“People across the country just fell in love with him,” said Christian Archer, a San Antonio-based Democratic strategist. “He was able to raise national-level money, and that’s just such a distinct advantage.”

However, Archer said, “There’s a fuse on that, and the question is how long will that last if he doesn’t make a move within a window of time.”

Archer said, “Right now, he’s on fire.”

If O’Rourke is giving donors any pause, it is largely because his fundraising came in a Senate contest, not a presidential primary stuffed full of marquee Democrats. New York Republican Rick Lazio, who set a single-quarter fundraising record in his losing New York Senate bid against Hillary Clinton in 2000 — a record surpassed by O’Rourke — failed to translate energy from that campaign into future political success. And in a lengthy presidential race, early stars can fade.

George Tsunis, the hotel magnate and Obama megadonor, said O’Rourke “performed very admirably” in the Senate race. But he was skeptical that O’Rourke could replicate his fundraising in a presidential race, saying many donors were likely motivated by anti-Cruz sentiment.

Still, Tsunis acknowledged the donor universe remains wide open. “A lot of people that I’m talking to are in a quandary,” he said. “They may have a half a dozen friends that are looking to do this, and they are so unbelievably torn here.”

There isn’t much modern historical precedent for O’Rourke to draw on. George H.W. Bush was a Texas congressman who won the presidency after an unsuccessful 1970 Senate bid. But his presidential run didn’t come until years later — and it took Bush two tries before winning the White House.

Abraham Lincoln ran for president — and won — after two losing campaigns for Senate. But the last person to go from the House to the presidency was James Garfield in 1880.

"One thing that [O’Rourke] is going to have to overcome is that he did lose to Ted Cruz," said Cappy McGarr, a Dallas-based investor and Democratic fundraiser. “He is the real deal, though. He’s charismatic, he’s thoughtful, he’s able — he is one of the most exciting politicians I’ve seen since Barack Obama ran for president.”

Like many donors, however, McGarr holds a favorable view of several potential contenders, including Biden, former New York City Mayor Michael Bloomberg, Sen. Sherrod Brown (D-Ohio), and Julián Castro, the former San Antonio mayor and Obama Cabinet secretary.

“I have a lot of friends who might be running for president, and I think the more the merrier,” McGarr said. “And I certainly wouldn’t preclude giving and raising monies for more than one candidate.”

Steve Westly, a former California state controller and major bundler of campaign contributions for Obama, said O’Rourke “has a lot of the wow factor now, and one could easily say, ‘He didn’t win.’ But to get [close] in Texas, that suggests to me that if he were the national nominee running against a non-Texan, he might well pull that state … and he is charismatic as heck.”

Westly said he does not “have complete conviction yet” about which candidate to support, with a primary field that appears “completely, totally different than anything I’ve seen in the last half century.”

Still, as he begins to field calls from potential candidates, Westly said he believes Democratic voters are “looking for newer faces outside the traditional Northeast corridor” of typical Democratic politicians, mentioning Bloomberg and Starbucks founder Howard Schultz, among others, as credible potential candidates.

Most years, Westly said, “Guys like me can say, ‘Hey, it’s going to be one or two people, it’s person A, B or C, here’s why. It’s a short discussion … it’s five minutes, we can narrow it down.”

In 2020, he said, “Here you have something fundamentally different … In terms of betting odds, it’s really hard to sort out.”

But Watts said O’Rourke could immediately narrow the field.

“I don’t’ believe that 50-year-old guys like me and 60-year-old guys in Washington who are in an hourly form of political warfare understand how disillusioned that warfare has made the younger people of this country,” he said. “From that perspective, Beto’s unvarnished approach was both refreshing to me, but intoxicating to the younger generation.”

“If Bernie runs and Warren runs and Kamala runs and [Cory] Booker runs, I think they all wash each other out in a certain way," Watts said. “Beto’s got the juice right now. If he goes, he’s going to suck a lot of the oxygen out of the room. A lot … and immediately.”