Beto's in for 2020.

Three-term former Rep. Beto O'Rourke, D-Texas, noted for his Bobby Kennedy resemblance, Jack Kerouac-style road trips, stream-of-consciousness ramblings and an oh-so-close bid to topple Texas Sen. Ted Cruz last year, ended months of speculation by announcing a White House bid in a video he sent to supporters sometime in the wee hours of Thursday morning.

"Amy and I are happy to share with you that I’m running to serve you as the next president of the United States of America," O'Rourke said. "This is a defining moment of truth for this country and for every single one of us. The challenges we face right now, the interconnected crises in our democracy and our climate, have never been greater.”

2020 DEMOCRATIC PRESIDENTIAL HOPEFULS TO TAKE STAGE AT SXSW; BETO O'ROURKE TO ATTEND FILM PREMIERE ABOUT FAILED SENATE BID

O’Rourke’s announcement came hours after the publication of a fawning article on the former congressman by Vanity Fair.

"I want to be in it," the former Texas congressman told the magazine. "Man, I'm just born to be in it, and want to do everything I humanly can for this country at this moment."

Since his announcement, O'Rourke has picked up an early endorsement from New York Rep. Kathleen Rice.

Republicans scoffed at his campaign launch, however, with RNC spokesman Michael Ahrens saying in a statement: “It’s telling that the Democrats’ biggest star is someone whose biggest accomplishment is losing. Beto O’Rourke failed to get anything done in Congress, and with extreme policies like government-run health care and tearing down border barriers, his 2020 bid won’t be successful either.”

The congressman from El Paso grabbed national attention last summer and autumn, as he challenged Republican Cruz in the 2018 midterm elections. O’Rourke raked in an eye-popping $80 million during his campaign, thanks in part to his uplifting message and his mastery of social media.

He quickly became a Democratic rock star. And like Sen. Bernie Sanders of Vermont, another darling of the party’s progressive base, O’Rourke quickly reached celebrity status, being referenced only by his first name.

O’Rourke narrowly lost to Cruz -- by just more than 200,000 votes out of more than 8 million cast. After his better-than-expected performance against the GOP incumbent, there were immediate calls by some Democrats for O’Rourke to run for president.

After saying days after the November elections that "I will not be a candidate for president in 2020,” O’Rourke quickly changed his tune, explaining that "I haven't made any decisions about anything yet.”

By mid-December, he acknowledged at a town hall that he was considering a White House run.

FULL COVERAGE OF 2020 ELECTION

Two national groups urging O’Rourke to launch a campaign sprung up just weeks after the 2018 midterms. In the ensuing months, the groups held house parties and other events in the early voting primary and caucus states as they built up lists of O’Rourke supporters.

In early January, with Beto mania at a fever pitch, O’Rourke live-streamed a visit to his dentist, which while going viral was also greeted with plenty of derision on social media.

Days later, as the Democratic presidential contenders were busy building organizations and making frequent stops in the early voting states, O’Rourke tried to find clarity. So he embarked on a solo road trip across the country, posting frequent travel log dispatches on Medium, the on-line publishing platform.

In a much anticipated early February interview with Oprah Winfrey, O’Rourke said he’d make a 2020 decision “really soon… before the end of this month.”

ALL YOU NEED TO KNOW ABOUT 2020 CANDIDATES

That deadline came and went.

Two weeks ago came word that O’Rourke had ruled out a 2020 Senate challenge against Sen. John Cornyn of Texas and would announce his decision on a presidential bid “soon.”

O'Rourke told reporters that he had made a decision, but remained mum on what he had decided.

"I want to make the announcement to everyone at the same time," O'Rourke explained. "I want to do it the right way."

This past weekend the apparent O’Rourke tease continued, as he attended the South by Southwest (SXSW) festival in Austin, Texas, for the premiere of a documentary about his 2018 Senate campaign.

He avoided revealing or detailing his 2020 intentions.

“I want to make sure I do it the right way and I tell everyone at the same time, so I’ll be doing that,” he once again told reporters when questioned about the delay in any announcement. “I’ve got to be on the timeline that works for my family and for the country.

As O’Rourke was in Austin, his deputy campaign manager from his 2018 Senate run sent an email to supporters inviting them “to be first to hear Beto’s big announcement.”

“I’m ready for us to bring our movement to the rest of the country,” Cynthia Cano added.

On Monday night, a video from O’Rourke on Twitter indicated that he would head this upcoming weekend to the state that votes first in the presidential caucus and primary calendar, to lend a hand to a Democratic state senate candidate running in a special election. The news came as O’Rourke reportedly had started staffing up in the Hawkeye State.

O’Rourke’s delay in making an announcement on launching a presidential campaign has some wondering if he missed his moment. A new national poll from Monmouth University indicated a slight deterioration in his popularity. O’Rourke enjoyed a 41 percent/9 percent favorable/unfavorable rating in January, when Beto fever was at its peak. Monmouth’s latest survey, released on Monday, indicated O’Rourke at 38 percent/12 percent favorable/unfavorable.

But other political analysts point to a lack of a breakout candidate so far in the large field of Democratic presidential contenders. They argue that a campaign launch by O’Rourke could shake things up. They are about to find out.