Beto O’Rourke, who has turned his consideration of a presidential campaign into an online version of reality television, inviting Americans to follow along through journal dispatches as he travels the country in search of personal clarity, said Wednesday that he had made his decision.

What is it? He’ll tell you soon.

When is soon? Unclear.

“Amy and I have made a decision about how we can best serve our country,” Mr. O’Rourke, the former congressman from Texas, said in the briefest of statements, referring to his wife, Amy Sanders. “We are excited to share it with everyone soon.”

[Stay up-to-date on the growing Democratic field with our candidate tracker.]

Mr. O’Rourke, who served in the House from 2013 through the beginning of 2019, made a national name for himself last year when he gave Senator Ted Cruz a surprisingly strong challenge in a reliably conservative state. Mr. Cruz was re-elected by less than three percentage points. Six years earlier, he had won by 16 points.

In his Senate campaign, Mr. O’Rourke fired up Texas Democrats with a broadly liberal message and a charismatic stage presence, while also pulling in donations from across the country.