The blustery wind gave the night air a bite that made it feel far colder than the low 50s, and by 8:15 p.m. Saturday, 45 minutes before the Beto O’Rourke rally was set to begin, there was not much of a crowd to speak of, leaving one to wonder whether, somewhere between his upbeat morning rally in El Paso and his afternoon rally at Texas Southern University in Houston, the political phenomenon’s bubble had burst.

But, by the time O’Rourke ascended the ersatz stage that had been constructed on Congress Avenue for his return to Austin for the first time as a candidate for president at just after 10:30 p.m., thousands of people had filled the streets in every direction, and the former congressman from El Paso, removing his jacket and rolling up his sleeves, seemed buoyed higher than ever.

“Austin, how you doin’?” O’Rourke asked. “We love you Austin. It is so good to be back here in Austin, the source of what is good for Texas and for the United States of America.”

WATCH: BETO O'ROURKE HOLDS RALLY IN DOWNTOWN AUSTIN

The three rallies Saturday were in the campaign’s description, kick off rallies, the official launch of his presidential campaign. But that came with a tweeted video way back on March 14, a seeming eon of political time ago, and these three rallies in the friendly terrain of his hometown of El Paso, in Houston, and in the shadow of the Capitol were homecomings for a favorite son who, after enduring a loss, had contemplated what that meant and what to do next and decided to reach higher.

Here was O’Rourke, saying that he wanted to serve them now as “the next president of the United States,” and, in the line that drew the most thunderous applause of the night, saying he wanted to defeat Donald Trump, that that was now to be his job.

PHOTO GALLERY: THOUSANDS TURN OUT TO SUPPORT BETO O'ROURKE IN AUSTIN

But it was state Rep. Gina Hinojosa, D-Austin, who said that they owed it to O’Rourke.

“What we started last year was a movement, a movement that brought Beto O’Rourke closer to being elected to the Senate than any Democrat of our generation,” Hinojosa said.

Hinojosa said that after what for Democrats were the devastating, shocking results of the 2016 election, O’Rourke, undaunted, put himself forward as a candidate for Senate.

"Beto just got back up and threw himself into the fight and gave it everything he had," Hinojosa said. "Beto believed in us before anyone else believed in us, even before we believed in ourselves.”

"That was Beto," Hinojosa said. "I stand with Beto today because Beto stood with us. He lifted us up, he propped us up until we remembered to stand on our own two feet."

"It’s time to throw down and fight with Beto,” Hinojosa said. “Because of the work you did in the last year, Texas is the battleground for 2020.”

Hinojosa’s father, Texas Democratic Party Chairman Gilberto Hinojosa, has in recent years had the thankless task of trying to lead the long-suffering party out of the electoral desert, thankless until 2018, the near-miss election of O’Rourke, and, as O'Rourke noted, the residual victories of Democratic candidates down ballot — flipping two congressional seats, a dozen state House seats, two state Senate seats, and a raft of judgeships.

“What you did in 2017 and 2018 was nothing short of a miracle," O'Rourke told his faithful.

Julie Cordero of Irving was there with her granddaughter, Madison Chargo, 9, her political compatriot and companion at women's marches in Washington, D.C., and Las Vegas and, Chargo said, "five or ten" O'Rourke events during his Senate campaign.

"It's his energy," said Cordero, who works for Customs and Border Enforcement at Dallas/Fort Worth Airport. "He listens to the people."

Cordero had wanted O'Rourke to run for the Senate again, against U.S. Sen. John Cornyn, R- Texas, in 2020. She thought he was the only hope of "turning Texas blue."

Julie Cordero & granddaughter Madison Chargo of Irving at@BetoORourke rally in Austin. Julie, who works Customs at DFW, was dismayed when he decided to run for President sted of Senate again b/c she thought only he could turn TX blue. But now good with Joaquin Castro for Senate.pic.twitter.com/8ykDH7SMkO

— jonathantilove (@JTiloveTX)March 31, 2019

But, as her presence at Saturday night's rally indicates, she's with O'Rourke now as a presidential candidate and she feels good about U.S. Rep. Joaquin Castro, D-San Antonio, as a worthy substitute for O'Rourke as the Democratic standard bearer in the Senate race. Castro has indicated a strong interest in running, even as his twin brother, Julián, is among the field of candidates running for presidents though, so far, without the fanfare attendant O'Rourke's newborn campaign.

"I've always liked the Castros," she said.

So too has Esmeralda Del Toro, who drove up from the Rio Grande Valley — she lives outside McAllen — for the Austin rally. She was an "ambassador" for O'Rourke's Senate campaign, a kind of super volunteer. She was prepared to support Julián Castro for president in 2020, until O'Rourke got into the race.

"They both stand for the same things but for some reason, Beto stands out more," Del Toro said."

Esmeralda Del Toro drove up from the Rio Grande Valley for the@BetoORourke rally in Austin. She also likes@JulianCastro. “They both stand for the same things but for some reason Beto stands out more.”pic.twitter.com/USssKjv0wq

— jonathantilove (@JTiloveTX)March 31, 2019

Hiram Garcia, a senior at the University of Texas where he leads the Longhorn League of United Latin American Citizens, was also a big O'Rourke supporter who interned in the Senate campaign. But he's not sure about he presidential run yet.

Like O'Rourke, Garcia is from El Paso, and his ambition is to someday hold the El Paso congressional seat that O'Rourke held for three terms and that is now held by Veronica Escobar, O'Rourke's dynamic successor who spoke at O'Rourke's rally in El Paso that began his day on Saturday.

Garcia, who talked with O'Rourke about his political ambitions when O'Rourke appeared at UT in September 2017 at an event sponsored by the Tejas Club, said he was "very surprised" that O'Rourke had decided to run for president. He said he was surprised because of how completely O'Rourke had disavowed any interest in running for president during his Senate run, and because of how obviously devoted he is to his wife and young children.

And also, Garcia said, because he was jumping into a "saturated race," with no shortage of other Democratic candidates.

That doesn't mean that he is ruling O'Rourke out — "I love Beto" — but Garcia said he wants to be very thoughtful and deliberate in choosing among some very good candidates, including he said, Mayor Pete Buttigieg, at 37 nearly a decade younger than the 46-year-old O'Rourke, who has caught a lot of positive attention recently.

Garcia said it is critically important that Democrats choose just the right candidate in 2020 because he thinks Trump is going to be very tough to beat with a strong economy and the conclusion of special counsel Robert Mueller that the president and his campaign did not collude with the Russians to influence the 2016 election.

Hiram Garcia, head of LULAC chapter at UT, talked with@BetoORourke about his desire to return to their hometown of El Paso to run for office. Surprised Beto decided to run for President and still deliberating about who he’ll back. Thinks@realDonaldTrump will be hard to beat.pic.twitter.com/ppNaQ7ssav

— jonathantilove (@JTiloveTX)March 31, 2019