SAN FRANCISCO — Sunday marks exactly eight months until the Iowa caucuses, but only a single, long-shot Democratic candidate in the party’s sprawling field, Representative Tim Ryan, spent the weekend campaigning there.
Instead, 14 White House hopefuls eschewed Iowa’s cozy church basements and V.F.W. posts to gather at a hangar-size convention center in this liberal hub, where they jostled for attention at the California Democratic Convention. And the party’s front-runner, Joseph R. Biden Jr., was speaking to L.G.B.T. activists in Ohio, a state better known as a general election battleground than a primary proving ground.
This weekend was no aberration: Democratic presidential contenders have already combined to visit more than 30 states and territories for public events, far more than in any past nominating contest when candidates would spend the vast majority of their time in Iowa and New Hampshire.
The explosive growth of social media, the increasing diversity of the Democratic electorate and changes to the party’s electoral calendar and debate format have created more of a national primary than ever before.
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.
This focus on breaking through online will only intensify this summer as the candidates strain to accumulate the 130,000 donors required for participation in the fall debates — a threshold that puts a higher premium on news media penetration than grass-roots organization.
“In the past, candidates chased big donors and endorsements,” said Donna Brazile, the former Democratic chairwoman. “Now they’re chasing individual donors and trying to make sure they can get on the stage where it all matters,” she added, referring to the televised debates.
The traditional early nominating states are hardly being ignored by the two-dozen candidates, and are still poised to play their usual role of winnowing the field. But they no longer have what was effectively a stranglehold on the time, money and attention of the White House aspirants in the year leading up to the primaries. And states like California that were once mere A.T.M.s for presidential hopefuls — who would fly in, raise money and leave — are welcoming candidates for traditional campaign events.
That is in part because of the increased importance of Super Tuesday, which has moved up on the calendar. That one day alone may offer more than 35 percent of all delegates and could include such large, racially diverse states as California and Texas. Early voting will take place in both states in the weeks usually dominated by the whiter states of Iowa and New Hampshire. This new focus on places whose demographics reflect the Democratic coalition, the party’s drift left and President Trump’s stunning election and divisive presidency have also elevated a different set of priorities in the campaign.
“If you’re looking at that calendar, and you know you can’t just win this with white voters, then you have to go to other states,” said Jess Morales Rocketto, a Democratic strategist, referring to the states with significant Hispanic and African-American populations that will cast ballots on Super Tuesday, which is taking place three days after heavily black South Carolina.
This approach represents a reversal from 2008.
In that race — the last Democratic contest with such a competitive, multicandidate field — Barack Obama was determined to prove to white and nonwhite voters alike that he had appeal in states with little diversity. He spent 89 days in Iowa leading up to his triumph at the caucuses, which demonstrated to skeptics that an African-American from Chicago could win over a heavily white and rural state.
This time, the Democratic contenders of all races want to demonstrate their commitment to inclusion and racial justice in hopes of winning over white progressives and people of color — while also showing that they can capture the states and voters that tipped the White House to Mr. Trump in 2016, especially in the industrial Midwest.
That has meant a vastly expanded political map, as the hopefuls touch down at historically black colleges in Texas and hurricane-ravaged Puerto Rico, while also visiting struggling industrial communities in Ohio and small towns devastated by opioids in West Virginia.
The question, and it is a particularly resonant one with early-state power brokers, is whether this shift is permanent and will only accelerate as the country grows more diverse and campaigns take place even more on smartphone screens than at county fairs. Or does it owe more to the unique nature of this race — an historically large field, an overriding hunger to defeat the incumbent and a front-loaded primary calendar — and would not necessarily reshape future nominating contests?
The answer may be found in who actually emerges as the Democratic standard-bearer, how they captured the nomination and their ultimate success or failure against Mr. Trump.
David Plouffe, the architect of Mr. Obama’s 2008 strategy, cautioned the party’s hopefuls not to lose sight of what he called “the North Star: what do I have to do in the early states.”
Everything, Mr. Plouffe said, should be built around that.
“The difference between third and fifth in Iowa could be the difference between staying in and dropping out of race,” he said. “And if you need to come in third but you came in fifth you’ll say, ‘Shoot, if only I had spent three or four more days in Iowa.’”
But the president himself, with his preference for arena rallies over living room give-and-take, proved that a candidate does not have to pay homage to every venerable primary ritual to win the nomination. And now most every one of the Democratic hopefuls is testing if they, too, can break from tradition and still claim the White House.
No candidate better illustrates how different this race is than Pete Buttigieg, the 37-year-old South Bend, Ind., mayor who at the start of the year was known to only the most dedicated political junkies. But a strong turn at a CNN town hall in March, a willingness to sit for just about any news media interview and an ability to get off pithy one-liners quickly endeared him to some Democrats, particularly upscale white voters taken with his literary references and multilingualism.
He has spent ample time in Iowa and New Hampshire, but he jumped in polls there because he was catching fire nationally — not because he won over activists one town hall at a time.
That is a lesson Beto O’Rourke discovered the hard way. Billed as a phenom after his do-it-yourself Senate campaign against Ted Cruz in Texas last year, Mr. O’Rourke sought to replicate the same improvisational approach upon entering the presidential race. He drove himself to campaign events, scheduled as many local events as he could and shunned the cable news circuit, telling supporters he would rather talk to them in person.
The strategy flopped. With no presence on television and an ever-growing Democratic field of candidates drawing more attention, Mr. O’Rourke, who ranked third in some early polls, saw his standing plummet. Now he is trying to resurrect his campaign in part by appearing on the cable programs that are the staples of the party’s most engaged voters, who watch to follow the primary and stay abreast of the latest Trumpian uproars.
And that, said Ms. Morales Rocketto, the strategist, is another factor that is driving this race beyond the realm of dutiful early-state voters: “Trump has accelerated engagement,” she said.
Mr. Biden, whom the president has elevated with near-daily attacks, is the most obvious beneficiary of the outsize role Mr. Trump is playing in this race. But another candidate has also been helped, though less noticeably, by taking on the president: Senator Elizabeth Warren.
While she has won plaudits on the left for her raft of ambitious policy proposals, an analysis of Ms. Warren’s recent improvement in the polls indicates that her growth coincides with an uptick in mentions on cable news — a jump that began after she called for Mr. Trump’s impeachment and then had an impressive showing on a CNN town hall last month.
Notably, Ms. Warren is strongest with liberal voters and those paying close attention to the race, precisely the Democrats most likely to be tuning into programs like “The Rachel Maddow Show” on MSNBC.
Ms. Warren and Mr. Sanders have been two of the most venturesome candidates when it comes to leaving the early states, and not because they are scheduling public events around their fund-raisers, like some of the other candidates. They have paid particular attention to holding events in heavily black communities in an effort to broaden their appeal beyond white liberals. Combined, they have visited nearly every state in the South.
Democrats in the early states have taken notice of what is happening. And they are most displeased about the new debate requirements, which they fear will only dilute what makes their nominating contests unique.
“It just pushes the campaigns to rely on social media platforms at the expense of building campaigns that have real people on the ground, knocking on doors and doing grass-roots campaigning,” said Jim Demers, a longtime New Hampshire activist.
“We have the tremendous opportunity to judge candidates based on face-to-face interaction,” he added, “and if we lose that it hurts the role Iowa and New Hampshire play.”