Updated at 6:10 p.m. with comment from Texas Sen. Ted Cruz.

WASHINGTON — El Paso Rep. Beto O’Rourke, the underdog Democrat hoping to defeat Sen. Ted Cruz in November, raised a record-setting $6.7 million in the first quarter of 2018, according to his campaign.

Outside of self-funding, that’s more than any Texan has raised in a single reporting period for a U.S. Senate contest in at least three decades, if not in history, according to data provided by the Federal Election Commission.

Former Lt. Gov. David Dewhurst, who lost to Cruz in a 2012 Republican primary runoff, reported $9.3 million in the third quarter of 2012, but that included more than $8 million of his own money.

O’Rourke’s tally, released by the campaign two weeks ahead of a federal filing deadline, is nearly triple his previous personal best — $2.4 million in the last three months of 2017.

And it shows growing momentum. O’Rourke raised $2.3 million in the first six weeks of the year and won the Democratic primary on March 6.

"It's clearly a sign of how badly Texans want change and want this country ... on the right course," O'Rourke said in an interview with The Dallas Morning News.

Cruz, who was campaigning in San Antonio on Tuesday, attributed the surge to energy on the "hard left."

"That's a whole lot of money. There's no doubt about that," Cruz told reporters, according to The Texas Tribune.

O’Rourke chalked up the momentum in part to his campaign strategy that’s included traveling to 228 of Texas’ 254 counties over the past year, and eschewing the aid of political action committees.

The O’Rourke campaign did not provide its latest cash-on-hand figure but said the $6.7 million comes from more than 141,000 individual contributions, with 70 percent from Texas donors.

“This is totally on the people of Texas, and the people of Texas are standing up and taking ownership of this campaign,” he said, adding: “This is less about a candidate and certainly not about a party, and all about Texas. I’m really just part of something larger that’s going on right now.”

U.S. Rep. Beto O'Rourke, D-El Paso, speaks while a donations jar is passed around the Brandon Community Center in Lufkin on Feb. 9, 2018. O'Rourke is running to unseat Sen. Ted Cruz, R-Texas, in the 2018 midterm elections. (Tamir Kalifa / The New York Times)

The news comes as Cruz, branding himself a "Tough as Texas" lawmaker, officially kicked off his general re-election campaign on Monday with a video focused on Hurricane Harvey relief efforts. Cruz is making a series of stops across the state this week and is scheduled to hold an event in Fort Worth on Wednesday.

The Cruz campaign has not yet released its latest fundraising figures, which aren’t due until April 15.

Through mid-February, Cruz raised more than $17 million for his Senate campaign account since taking office in 2013. Cruz raised nearly $5.8 million since O'Rourke entered the contest a year ago, though that doesn't include the last six weeks. His April 15 report will show whether he has lagged the challenger for the full year.

Analysts say O’Rourke needs north of $20 million to $25 million to launch a credible challenge to the Republican incumbent.

So far, he’s raised more than $13 million, with months to go before the general election contest. Asked his fundraising goal, O’Rourke said: “Just as much as we can.”

Fundraising a focus

Though the contest isn’t considered among the most competitive nationally, the race has garnered widespread attention because of the candidates’ fundraising.

According to the Center for Responsive Politics, the Texas contest ranks second of all 2018 Senate races in candidate fundraising — around $26.3 million combined, through mid-February— and first in spending, at more than $16 million.

President Donald Trump talks with Texas Sen. Ted Cruz during a White House event regarding the modernization of the nation's air traffic control system on June 5, 2017. (File Photo / Getty Images)

Analysts attribute much of O’Rourke’s fundraising success to anti-Trump and even anti-Cruz sentiment, as well as online conduits, such as ActBlue, that allow donors to give small amounts of money to Democratic candidates.

“The shock of Donald Trump in the Oval Office has spurred Democrats to march in the streets, to donate to candidates, to become candidates themselves. The congressman has benefited from that,” said Nathan Gonzales, of Inside Elections, which provides nonpartisan analysis of campaigns for Senate, House, governor and president.

O’Rourke captured just 62 percent in the Democratic primary, a sign that he has a ways to go in raising his profile. But Cruz, a former presidential candidate, has near universal name ID and is widely reviled by Democrats, which works in the challenger’s favor.

“They might not know who Beto O’Rourke is, but they know who Ted Cruz is and they know they don’t want him in Washington,” Gonzales said. “If Beto was running against [Wyoming Sen.] John Barrasso, he wouldn’t be raising the same amount of money.”

Seth McKee, a political scientist at Texas Tech University, said O’Rourke’s fundraising indicates O’Rourke can present a “real challenge” to Cruz and is gaining the resources he’ll need to raise his name ID.

But O’Rourke still faces considerable headwinds when it comes to voter turnout among Democrats, particularly in a midterm year, which typically favors the GOP.

Though Democrats nearly doubled their numbers since the last midterm election, from 560,000 to more than one million in March, Republicans still outvoted them, with 1.5 million casting ballots in the primaries.

“Maybe that’s why Cruz seems so confident. He just doesn’t think that coalition will show up for O’Rourke and he’s probably right,” McKee said.

He doesn’t think O’Rourke’s victory is impossible, but is “improbable,” given the state's political landscape.

Cruz advantage

The three-term congressman has sworn off political action committees and outraised Cruz several times since announcing his candidacy in March 2017.

Still, Cruz maintained a more than $1 million advantage over O’Rourke going into the March 6 primary, according to federal reports filed in mid-February, with Cruz holding $6 million in cash compared with O’Rourke’s $4.9 million.

Although O’Rourke’s quarterly tally sets a Texas record for a Senate race dating at least to 1976 — and does not include spending by outside groups — nationwide, more than 30 Senate candidates have raised more in a single reporting period, according to FEC data.

In 2010, Republican Linda McMahon, an American professional wrestling magnate, loaned her Senate campaign $20 million in a single quarter as part of her unsuccessful contest against Richard Blumenthal in Connecticut. She now leads the Small Business Administration under Trump.

That same year, tea party candidate Sharron Angle raised more than $14 million in a single quarter in a failed bid to unseat Nevada Democrat Harry Reid, the Senate majority leader at the time.

Last year, Alabama Senate hopeful Doug Jones — who defeated controversial GOP candidate Roy Moore to succeed Attorney General Jeff Sessions in the chamber — raised more than $10 million in two reporting periods for his special election contest.

CORRECTION, 10:30 p.m., April 4, 2018: An earlier version of this story overstated the total amount of O'Rourke's fundraising. He's raised more than $13 million since entering the race, not $15 million.