It's not so charming if you're, say, Ted Cruz, who is one of many Texans to complain that his opponent is spamming him with unwanted texts.
But O'Rourke's text message program took a turn Wednesday, when the campaign said an "impostor" volunteer infiltrated the system and asked voters for help ferrying "undocumented immigrants to polling booths."
Frank Freeman, an espresso machine repairman in Houston who plans to vote for O'Rourke, said he signed up for the text messages a few weeks ago and had become used to them. They came from different numbers and different volunteers, he said — once inviting him to a town hall, once to a block walk. Sometimes he replied, and sometimes he didn't.
Just before 4 p.m. Wednesday, he got a new one from a certain "Patsy."
"The language was spot on," Freeman said. "It all looked right until you get to the 'undocumented' part. That told me, well, something's up with this."
It's unclear how many people got the message — but several thousand saw or shared Freeman's image of it on Twitter, and others told Texas news outlets that they received exactly the same text at nearly the same time.
A couple of hours later, Freeman got another text from the campaign confirming his suspicions.
"Hi Frank, this is Katrien the Texting Team manager on the Beto for Texas campaign," it read. "An impostor signed up to be a volunteer on our texting team and texted you today with a message that was not approved by the campaign. We're very sorry about this."
An O'Rourke spokesman, Chris Evans, told The Washington Post that the impostor sent two texts Wednesday — the second one said it was polling voters about their views on socialism — before the campaign found out and cut off the person's access. He said the campaign was looking into how the program was accessed.
O'Rourke has been drawing crowds across Texas and interest across the country for his campaign against Cruz, who has recently gotten the support of President Trump, who beat Cruz in the 2016 presidential primary. Texans haven't picked a Democrat for a statewide office since 1994, but the race has become one of the most expensive Senate contests in the country. Polling shows Cruz with a narrow lead.
O'Rourke is one of the latest politicians to incorporate mass texting technologies into his voter outreach programs, for better or worse. The campaign uses a "peer-to-peer" texting service called Relay, which allows a single volunteer to field conversations with hundreds of potential voters — much like an online shopper can now pull up a chat window and reach a customer service agent at will.
"The person who sent the texts was not affiliated with Relay," a spokesman for the company told The Washington Post. He referred questions to the campaign for details. "It is part and parcel of running any kind of large-scale volunteer effort," he said. "The best way for campaigns to protect against this is to have strong systems for volunteer vetting, training, and ongoing monitoring."
The O'Rourke campaign said it has taken steps to make sure no more trolls get into the system.
An unofficial YouTube tutorial for volunteers on the campaign's "texting team" suggests how Patsy managed to do it in the first place.
According to the video, volunteers simply sign on to Relay, where they might find "500 to 800" prewritten text messages in their in-box, waiting to be sent out: "Hi Robert, this is Emily volunteering w/ Beto for Texas."
Depending on how Robert responds — with enthusiasm, anger or confusion as to how the campaign got his number — the volunteer can write back with one of a dozen suggested responses.
But at all times during this conversation, a big text window with a smiley face invites the volunteers to ad-lib their own comments — injecting a bit of personality into an otherwise prescripted campaign drive, which is apparently what "Patsy" did Wednesday.