EL SEGUNDO, Calif. — In Iowa, they pause for coffee at the Kum & Go convenience stores in crossroads scattered around the state. In New Hampshire, they engage voters in school gymnasiums and on town street corners. Here, they appear on television.

They’ve been doing it this way for a third of a century. The greatest insight in modern California political history may have come in 1986, when Democratic Sen. Alan Cranston was fending off a challenge from GOP Rep. Ed Zschau. “A campaign rally in California,” Democratic political strategist Robert Shrum said at the time, “is three people sitting around a television set.”

Today Shrum is the director of the Center for the Political Future at the University of Southern California. Perched in the state that cultivates change — that has made change the enduring characteristic of its culture — he believes little has changed. The Michael Bloomberg campaign soon will reach the quarter-billion-dollar mark in television spending, much of it here. He’s added tens of millions on digital ads, which don’t even require three people holding an iPhone. He may have been New York’s mayor, but he understands California perfectly.

Next week, California and 13 other states hold “Super Tuesday” contests awarding a third of the delegates required to win the Democratic presidential election. Campaigning in the most important primary of the most important campaign day bears no resemblance to what the other candidates did for months in Iowa, New Hampshire and Nevada. The long-running candidates are recalibrating. Bloomberg is watching his ads settle into the consciousness of California.

And though Bloomberg, reeling from a disastrous debate performance in Nevada, may be attempting to be up close and personal with his television blitz, he is not doing it at close range and there is nothing personal about it. It isn’t a peculiarity of Bloomberg. It is a peculiarity of politics here.

“People here don’t go to political rallies,” Shrum said the other day. “After you fight your way home at night through the traffic, the last thing you want to do is to go out and go to a rally for some politician.”

That explains the Bloomberg approach, though it doesn’t explain how a California-style campaign conducted without campaigning can be in a tie for fourth place (with former Mayor Pete Buttigieg of South Bend, Indiana, who was in a virtual tie at the top of the first two contests), according to a poll released last week by the respected Public Policy Institute of California.

But another factor explains why Sen. Bernie Sanders of Vermont holds a commanding lead in that poll, with 32 percent of those surveyed — far more than the 12 percent that both Buttigieg and Bloomberg claim.

California — which voted Republican in six consecutive presidential elections between 1968 (native son Richard M. Nixon) and 1988 (George H.W. Bush, the heir to two-term California governor Ronald Reagan) — has voted Democratic the past seven elections, from Bill Clinton in 1992 to his wife, Hillary Clinton, in 2016. Ms. Clinton defeated Donald Trump by a margin of nearly 2-to-1. Her California bulge accounted for her victory in the popular vote.

Once a bastion of conservative Republicanism, California now is a redoubt of progressivism, and Sanders suits this state just right. He is the modern incarnation of Upton Sinclair, who lost a landmark 1934 gubernatorial race to Republican Frank Merriman, but who displayed many of the characteristics that account for Sanders’ appeal nearly a century later. Sinclair, best remembered as the author of the muckraking novel “The Jungle,” was a socialist who ran as a Democrat; his EPIC (End Poverty in California) plan spooked the political establishment and business interests; and he cared little for the conventions of politics.

This strain of modern California politics may not provide the breakthrough Bloomberg covets.

Politics here is sensitive to the inclinations of women and minorities, who have not found comfort in late-breaking stories about Bloomberg’s coarseness with women and his support for “stop-and-frisk” procedures in New York. Bloomberg has apologized for the latter. The former may still sting him. And he faced relentless criticism during the Nevada debate Wednesday from other candidates for “buying the election.”

Sanders’ lead is impressive, but more impressive is his 2-to-1 lead over former Vice President Joseph R. Biden Jr. as the candidate Democratic voters think is most likely to defeat President Trump.

The Sanders support here skews young. More voters 44 and younger support the Vermonter than all the other candidates combined, according to the policy institute poll. A separate survey undertaken for Tufts University’s Tisch College shows Sanders leading among younger voters in Texas, the second biggest Super Tuesday delegate prize, by a substantial margin. The most intriguing element of the survey: Two in five of these younger Texans plan to vote.

Perhaps. Less than half of those 18 to 29 voted in the 2016 general election — the only age group where a majority did not go to the polls. Earlier this month, in New Hampshire, those aged 18 to 29 accounted for only one-seventh of those who voted.

Another uncertainty: late deciders. About half the New Hampshire electorate made its choice in the final days before the primary. (Buttigieg and Sen. Amy Klobuchar of Minnesota were the principal beneficiaries of those who kept their minds open until the end.) There are suggestions that that phenomenon will repeat itself in California, which permits early voting by mail. Early indications suggest that voters are holding back before making their decisions — or sending in their ballots, which are running 7,000 behind the 2016 pace.

Jack Kerouac, like this year’s presidential candidates marked by his life on the road, described California in 1957 as “wild, sweaty, important, the land of lonely and exiled and eccentric lovers come to forgather like birds, and the land where everybody somehow looked like broken-down, handsome, decadent movie actors.”

In the next week, presidential candidates will come here, in person or on television, to forgather like birds. Most of them will leave broken-down. For Biden, for Sen. Elizabeth Warren of Massachusetts, almost certainly for Klobuchar, California is the crucial crucible of this campaign. And it is the great testing ground for Sanders and for Bloomberg, two New Yorkers California dreamin’.