WASHINGTON — Senator Bernie Sanders seemed nervous. In just two hours, he would conduct a live-streamed town hall event on the Iran nuclear deal, and he still hadn’t nailed his opening.
“Did you mention to somebody doing a history of U.S.-Iranian relations?” he asked aides who had gathered in his Senate office to help him prepare. “What do you think about starting with that?” Then he wanted to say something about Saudi Arabia. Then Israel.
In another room, staff members rushed to finalize last-minute details. “We convert into a small production company,” one aide joked.
The town hall meeting in mid-May came off seamlessly, before a modest live audience at the Capitol Visitor Center. Mr. Sanders scripted the evening’s event, interviewed panelists and directed the conversation. There were no nettlesome questions from television or newspaper reporters. And over the next two weeks the real target audience — online viewers — would show up in droves, with some 800,000 people watching it.
The event provided a behind-the-scenes glimpse into the grass-roots efforts Mr. Sanders has become known for, as his team revved up its campaign engine: A week later, Mr. Sanders would announce his bid for re-election to the Senate. The democratic socialist from Vermont is also widely believed to be considering another run for president in 2020.
But the Iran discussion also reflected the kind of direct-to-voter messaging strategy that has become increasingly common among politicians — both as a way to shape information about their goals and to avoid difficult questions from the news media, particularly in the midst of scandal or controversy. From Washington to Texas to California, politicians are road-testing their political messaging strategies, searching for the best way to reach voters in ways that often bypass the traditional media gatekeepers.
The Iran town hall event would be the third Mr. Sanders has held this year; more than one million people viewed the first, on health care, and roughly 2.5 million watched the second, on inequality, according to Mr. Sanders’s team.
Senator Sherrod Brown of Ohio and Representative Sean Duffy of Wisconsin, both running this year, have started podcasts, with humanizing names like “Canarycast” and “Plaidcast.” Representative Devin Nunes of California has his own local news site, The California Republican, which is paid for by his campaign committee. Representative Beto O’Rourke, a Democrat making a long-shot bid to unseat Senator Ted Cruz of Texas, is streaming his entire campaign live on Facebook. And many other politicians are now routinely Instagramming and Facebooking, tweeting and Snapchatting.
These media methods have obvious appeal: Politicians can appear accessible but remain insulated from the press. They are also not altogether new. President Trump eschewed traditional television advertising during the 2016 campaign and can now overshadow even his own party’s message at the drop of a tweet. And many politicians have long made a practice of…