The shift reflects the new imperatives driving campaign strategy. With voters increasingly consuming news online, candidates are eager to go viral, which helps build their grass-roots and small-donor networks. This has made the feedback loop between the internet and television news the most powerful tidal force in politics, prompting campaigns to approach states as would-be soundstages for specific messages they are trying to deliver and constituencies they are hoping to reach.

One sign of a successful event, according to campaign aides working in this primary: Did cable news stations televise live from the venue?

“You don’t have to be in Des Moines or Manchester to have a viral moment and if that happens you’re in front of millions of people and can raise potentially millions of dollars,” said Tad Devine, a longtime Democratic strategist.