While other candidates were assembling campaign staffs and volunteer armies in early nominating states, O’Rourke lacked the infrastructure necessary to organize his own supporters. Lawmakers and major Democratic donors could not get calls returned. When the campaign’s skeletal staff promised to reach out, it sometimes forgot.

The signs of disorder were startling. He announced his candidacy before hiring a campaign manager. Two senior officials who had worked on O’Rourke’s Senate run and on Sanders’ 2016 presidential campaign, Becky Bond and Zack Malitz, abruptly left. On the eve of his campaign announcement, O’Rourke was forced to personally apologize to at least one prominent Iowa Democrat for his lack of organization, according to a source familiar with the conversation.

O’Rourke’s initial handling of the media was just as clumsy. He alienated reporters by refusing to provide basic information about his schedule — including, for many outlets, the location of his campaign’s first public event. He later acknowledged he needed to do a “better job” reaching a national audience.

But at first, he believed he didn’t have to — that based on the success of his Senate campaign’s social media effort, he could largely bypass the traditional press, two people familiar with the campaign said.