Beto O'Rourke has decided not to run for U.S. Senate next year against Texas Republican incumbent John Cornyn and likely will announce a campaign for president soon, people close to the former El Paso congressman told The Dallas Morning News on Wednesday.

Numerous people close to O'Rourke said they expect him to announce his presidential campaign within weeks. O'Rourke on Wednesday wouldn't reveal his political plans except to say he has made up his mind.

"Amy and I have made a decision about how we can best serve our country," he said in an exclusive statement to The Dallas Morning News. "We are excited to share it with everyone soon."

Since his close but historic loss to GOP Sen. Ted Cruz in November, O'Rourke has been weighing how to "best serve the country." His political options have been to run for president or against Cornyn.

Should he decide on a White House run, O'Rourke would join a large Democratic Party primary field. He's behind much of the field in fundraising, developing an organization and getting in front of voters.

A December Des Moines Register poll showed O'Rourke trailing only former Vice President Joe Biden and Vermont Sen. Bernie Sanders for the Democratic Party nomination for president. O'Rourke finished first nationally in a straw poll conducted among members of the progressive group MoveOn.org.

But since then, candidates including Sen. Kamala Harris of California have risen in the polls and appear to be getting traction in early battleground states like Iowa.

"It seems like his star was fading," said University of Iowa political scientist Tim Hagle. "That would be because he's not in the news."

Hagle said O'Rourke still has time to make inroads in the contest.

"I don't know that O'Rourke has missed his opportunity, but he does need to get in the race," he said.

Dallas County Judge Clay Jenkins, who said he has helped talk O'Rourke through his decision, said O'Rourke would make a good presidential candidate.

"He has a message that is the right antidote to Donald Trump," Jenkins said. "He also has the ability to create his own buzz. That message involves bringing people together and solving problems."

President or Senate run

Some Texas Democrats had hoped that O'Rourke would abandon thoughts of running for president and challenge Cornyn instead.

Rep. Eddie Bernice Johnson said this week on Lone Star Politics that she recently texted O'Rourke and urged him to run for Senate.

"I would love for him to stay Texas-focused," Johnson said she told O'Rourke, who texted her back: "I love you and I appreciate your friendship."

Texas Democratic Party Chairman Gilberto Hinojosa has also said O'Rourke's best fit would be in a Senate race, but respected his desire to explore a run for president.

Cornyn has said Republicans should learn lessons from O'Rourke's close finish against Cruz, and Cornyn has already hired staff and been raising money in anticipation of a showdown with O'Rourke.

"We're all waiting with bated breath for Beto to announce his decision," Cornyn told reporters in a conference call Wednesday. "In all seriousness it makes no difference to me what he decides ... or whoever's nominated by the Democrats for the Senate in 2020. No doubt Beto was a phenom in 2018, primarily because he was able to raise $80 million, which is an unprecedented amount of money in a Senate race in Texas."

Cornyn said he was preparing to run against O'Rourke or someone else.

"Whoever decides to run for president, let 'em have it, and if they want to run for Senate, we'll be ready," Cornyn told Texas reporters earlier Wednesday on a weekly call.

O'Rourke's run-up

For weeks, O'Rourke has been leaning toward a national campaign.

On Feb. 5, he discussed his future with Oprah Winfrey, telling her that he has "been thinking about running for president."

"We want to play as great a role as possible making sure that this country lives up to our expectations, to the promise, to the potential that we all know her to have," he told Winfrey in front of an audience in New York City's Times Square.

In February, O'Rourke has had two speaking engagements outside the state: in Illinois at a national conference of the United States Hispanic Leadership Institute and at the University of Wisconsin. He also spoke to students at a technical college in Milwaukee and at Columbia University in New York.

Last week in El Paso, O'Rourke offered additional clues that he wasn't interested in challenging Cornyn, including mentioning his bipartisan work with the senior senator as he received the El Pasoan of the Year Award at Fort Bliss.

Though sources say O'Rourke intends to run for president, if his campaign fizzles before the early primary contests, a Senate run could be revisited.

"Beto has the unique circumstance that Texans will support him whether he runs for president or for Senate," said Matt Angle, founder and director of the progressive Lone Star Project. "Texans would be happy with him in any scenario."

Texas law also allows for O'Rourke to run for president and Senate at the same time, though sources say O'Rourke does not intend to do that.

Voters across the country took notice of O'Rourke's campaign against Cruz, and for a presidential contest, he'll have to retrofit that approach for a larger audience.

Molly Hanchey, a Dallas activist and a grass-roots leader in Barack Obama's 2008 Texas presidential campaign, said the former president was "authentic, inspirational and persuasive."

"To be able to have that kind of personal power is an extraordinary thing," Hanchey said. "I get the sense that Beto is that same kind of guy. He knows who he is. He stands his ground."

Ron Kirk, the former Dallas mayor and U.S. trade representative, said this week that O'Rourke would be a strong candidate, but warned that he needed to have a more structured campaign. The former El Paso congressman focused on volunteers and field organizers instead of paid consultants and high-level staff.

"One of his positives is also a liability," said Kirk, who ran unsuccessfully against Cornyn in 2002. "He was able to run an unconventional campaign. It's one thing to drive around Texas. He has to put together much more of a traditional campaign to manage the demands of a national race."

Kirk added that O'Rourke, at this point, has as good a chance as almost anyone else in the race.

"It's anybody's game," he said. "He's got to put on his big-boy pants and get in there and fight."

Washington bureau chief Todd J. Gillman contributed to this report.