Washington (CNN) As Beto O'Rourke weighs whether to run for president in 2020, he and his top aides are carefully keeping alive expectations that he'll ultimately seek the Democratic nomination.

In meetings, calls and text messages, the 46-year-old former congressman from Texas and his aides and advisers are -- without committing to anything -- talking through the contours and challenges of a presidential run and evaluating potential staff and supporters.

The decision on whether to run is unlikely to come before February at the earliest, two sources close to O'Rourke said. Should he run, he would enter the race a top-tier candidate, bringing a massive small-dollar donor base and a sharp stylistic clash with President Donald Trump into a wide-open Democratic contest.

On Tuesday, an hour after Trump delivered a nationally televised speech about border security, O'Rourke was walking with a friend through the streets of El Paso, along the southern US border, on Facebook Live . He said that if Americans could come and experience the city, "all of this consternation and fear" about immigration and the border "would melt away."

O'Rourke's camp is feeding the speculation of a presidential campaign in subtle ways -- ranging from keeping his email list active to green-lighting public declarations of support.

"He could easily send a message that he didn't want this to happen, and he hasn't done that," said Tyler Jones, a veteran South Carolina Democratic operative who this week joined an outside effort to draft O'Rourke into the 2020 race.

Since his failed bid to unseat Sen. Ted Cruz in Texas, several likely Democratic presidential candidates, eager to see what O'Rourke will do next, have reached out, sources familiar with the calls said. California Sen. Kamala Harris spoke with O'Rourke by phone. Massachusetts Sen. Elizabeth Warren left a voicemail.

O'Rourke met in mid-December with Martin O'Malley, the former Maryland governor who ran for president in 2016. O'Malley had decided he would not run again, and he wanted to use his exit from the field of possible contenders to highlight the person he thought the party should nominate.

Weeks later, O'Malley checked in with David Wysong, O'Rourke's longtime top aide. He wanted to know if, by backing a potential O'Rourke candidacy, he would be walking out onto a limb that was about to be sawed off.

Wysong told O'Malley to go ahead, a source familiar with the conversation said. And soon afterward, the Des Moines Register published an op-ed by O'Malley -- the text of which O'Rourke's camp said it hadn't seen beforehand. The first sentence: "I will not be running for president in 2020, but I hope Beto O'Rourke does."

It was one in a series of moves that have fanned speculation about an O'Rourke presidential run as O'Rourke personally takes time off after a two-year Senate campaign in which a defining feature was his constant travel to all 254 counties in Texas.

In November, O'Rourke took to Medium with a post that was literally about running through Washington, but that many took metaphorically. In December, his wife, Amy, wrote a Medium post about the Senate campaign: "My hope is that as I continue to share these moments with our kids, they will see that even though we lost the election, this was the best possible way we could have spent the past two years."

O'Rourke has asked aides to plan a road trip in February, the Wall Street Journal reported Monday. The trip would keep him out of the early-voting states and would involve pop-ins at various stops with no staff and no press -- though he would likely livestream much of the trip.

O'Rourke has largely been at home in El Paso in recent weeks, spending time with his three young children, who go back to school later this week. His friends and political advisers say he hasn't made a decision on whether to run for president, but that in recent weeks he has been reaching out to ask for advice and talk it over.

"I think he's considering it very seriously," said Steve Ortega, an O'Rourke friend and El Paso political veteran.

"His primary concern right now is the effect it would have on his family, so he wants to make sure his wife is totally on board. And probably where he has the biggest area of concern is the children, just because they already went through a tough Senate race. And by tough, I mean their dad wasn't around for a lot of things," Ortega said.

O'Rourke publicly opened the door to a presidential campaign in December, when he acknowledged at an El Paso town hall that the hard "no" he'd delivered when asked about 2020 before had softened.

But no one is getting a firm answer at this point about O'Rourke's future.

Over the holidays, O'Rourke returned some of the calls and texts that had amassed from Democrats -- including operatives in states that vote early in the presidential nominating process.

But his message was noncommittal. He thanked them for reaching out and told them they'd be among the first to know if he decided to run, sources on the receiving end of those messages said.

Wysong, O'Rourke's longtime chief of staff and the manager of his Senate campaign, has been the point person for conversations with Democratic operatives interested in working on a potential O'Rourke campaign. He and other O'Rourke aides have spoken with early-state political veterans, including some who worked on former President Barack Obama's campaigns, multiple sources who have spoken with O'Rourke's camp said.

Early-state Democratic officials have tried without success to get O'Rourke to visit. Sean Bagniewski, the Democratic chairman in Iowa's Polk County, the home of Des Moines, said he hasn't heard anything back from O'Rourke's camp. That, an O'Rourke aide said, is typical: They aren't accepting or rejecting any early-state invites at this point -- leaving them to pile up, largely unanswered.

Without an answer from O'Rourke, efforts to draft him into the 2020 race have ramped up, as well.

Draft Beto, a political action committee that launched in December with a goal of raising $1 million in an escrow account and organizing in the early states in case he does run for president, plans to release a video Wednesday that will showcase O'Rourke as a viral sensation.

The group also brought on new early-state advisers -- including Jones, who was O'Malley's state director in 2016, and former state lawmaker Boyd Brown, O'Malley's 2016 state chairman. The two had been part of efforts to draft then-Vice President Joe Biden into the race in 2016.

In South Carolina, Jones said there are "two big elephants in the room" -- Biden and O'Rourke -- and that many Democrats are waiting to see what the two will do before deciding who they will support.

Michael Soneff, who worked with the Nevada Democratic Party on congressional campaigns last year, joined Draft Beto as a Nevada adviser.

The group is also close to adding an Iowa adviser, said its co-founder Nate Lerner, and is speaking with veterans of Obama's administration about roles.

"Every other candidate would kill for the kind of energy he has," Lerner said. "We want to show the real energy that does exist."

As O'Rourke makes up his mind, top-shelf Democratic talent is waiting for him before leaping to other campaigns, even as the race to staff up accelerated in recent days with Warren's hiring of four experienced Iowa operatives and a former top Obama hand.

Becky Bond and Zack Malitz, veterans of Sen. Bernie Sanders' 2016 presidential campaign who built out O'Rourke's "distributed organizing" system of small outposts throughout Texas staffed by dedicated volunteers, are among those now hoping to work on an O'Rourke campaign.

That view is nearly unanimous among O'Rourke's advisers and allies, even as some Texas Democrats hope instead to see him run for statewide office again in 2020.

The belief in O'Rourke's camp is that his approach -- including his rejection of all donations from political groups, his comfort delivering progressive messages in heavily Republican areas, at times turning those messages into the viral moments that built his national following and his willingness to livestream nearly everything he does -- uniquely suits him to a political environment in which Trump commands constant media attention and voters reward authenticity.

O'Rourke got attention, and nearly 100,000 retweets, when on December 28 he tweeted a 48-second video attacking Trump's argument for a border wall and calling it a "symbol of division." The video featured images of the Rio Grande river with text, and O'Rourke doesn't even appear in it.

His massive email list, which O'Rourke leveraged to raise $80 million in his failed run against Cruz, smashing previous fundraising records for Senate races, is a valuable asset O'Rourke's team is making sure to keep active, sending supporters three emails since November's midterm elections.

For his friends in El Paso -- many of whom were in Washington last week for the swearing-in of Rep. Veronica Escobar, who rose in politics at the same time as O'Rourke and won his old House seat last year -- an O'Rourke presidential run would be a way to counter Trump's immigration rhetoric with a candidate who is bilingual and from a city just across the border from Ciudad Juárez.