Bernie Sanders has changed since 2016, but so has the...

Sen. Bernie Sanders is doing a few things differently in his second run for president. For one, he’s talking about himself.

The 77-year-old Vermont independent — who will hold a rally Sunday at Fort Mason in San Francisco — now peppers speeches and fundraising pitches with stories about how his lower-middle-class upbringing in Brooklyn shaped the policies he’s championed for decades. He talks about his father, a Polish Jew, who immigrated to America “without a nickel in his pocket” when he was 17.

Sanders rarely mentioned any personal details during his 2016 campaign. His advisers hope the humanizing touches will help, even though this approach “is a little outside of his comfort zone,” said Fremont Democratic Rep. Ro Khanna, a co-chair of Sanders’ presidential campaign.

Khanna said he and others urged Sanders to include more of his life story because “it was really compelling.”

“It’s the story of an underdog,” Khanna said. “He always says, ‘Oh, you guys tell my story.’ He believes politics should be about ideas. He doesn’t want to trade on his biography. But I think it makes him far more relatable to folks.”

It is one of several differences between Sanders’ 2016 campaign and this year’s version. Insiders say this campaign is more organized than the one that sneaked up on Hillary Clinton. Its leadership is more diverse. And Sanders is broadening his 2016 talking points to appeal to voters who think the justice system is stacked against racial minorities.

But the electoral landscape has also changed dramatically for Sanders. He’s not facing one competitor for the Democratic nomination — there are 14, perhaps with more to come.

And he’s not the insurgent outsider anymore. Sanders isn’t the only candidate supporting ideas like a single-payer health care plan — several of his rivals are, too.

Changes for Sanders include:

His organization: “Last time it was a lot of broken field running,” said RoseAnn DeMoro, the former head of the National Nurses United union and a longtime Sanders confidant. “Bernie took himself by surprise. ... But this time, he is deadly serious he can win.”

Insiders say there is a more professional air to the campaign. Sanders didn’t even have a pollster until a couple of months before the Iowa caucuses in 2016. For this run, he’s already got one.

Sanders has diversified his staff after criticism that his 2016 organization was too white and male. His top advisers include Khanna, the son of Indian immigrants, and former Ohio legislator Nina Turner, who is African American. His campaign manager is Faiz Shakir, a Pakistani American who most recently was the political director of the American Civil Liberties Union. His political director is Analilia Mejia, a longtime community and labor organizer whose mother was an undocumented immigrant from Colombia.

“There’s clear difference in his staffing. He’s bringing on many heavy hitters — including many women and people of color — and that’s impacting how he’s taking his core economic message and working to make it more inclusive,” said Adam Green, co-founder of the million-member Progressive Change Campaign Committee, which has endorsed Sen. Elizabeth Warren of Massachusetts for president.

It wasn’t just Sanders’ staffers who were overwhelmingly white in 2016 — so were his voters. The senator’s failure to connect with African Americans gave Clinton a free ride through Southern states and a huge pile of delegates.

In a speech this month in North Charleston, S.C. — an early primary state where 60 percent of the Democratic electorate is African American — Sanders added something he didn’t often say in 2016.

“Our campaign is about fundamentally ending the disparity of wealth, income and power in this country,” he said. “But as we do that, we must also address the disparity within the disparity — the outrageous levels of racial disparity that currently exist.”

A different challenge: In 2016, Sanders could portray himself as an underdog taking on Clinton, the establishment candidate who had vastly more name recognition, money and a network of donors and supporters across the country.

Now, at least pending former Vice President Joe Biden’s expected entry in the race, Sanders is the front-runner. He said he raised more than $5.9 million in the first 24 hours after he announced his candidacy in February, tops in the self-reporting field until former Rep. Beto O’Rourke claimed a $6.1 million first-day haul this month.

This time around, Sanders is the candidate with “a 50-state infrastructure of volunteers, small donors and identified supporters,” said former San Francisco Supervisor Jane Kim, a Sanders supporter who is not affiliated with the campaign.

The downside: Sanders “is less of an unknown this time, so it’s harder for him to campaign as the fresh new face,” said Danielle Vinson, a professor of political science at Furman University in South Carolina.

The issues: Sanders has company. Several of his new competitors are staking out the positions he had to himself in 2016. Sens. Warren, Kamala Harris of California and Kirsten Gillibrand of New York, among others, support Medicare for All. Harris is among those who back free public college tuition.

“There are other people who claim the same progressive lane that he did — and they’re younger and fresher faces,” said Dennis Goldford, a political science professor at Drake University in Iowa.

But his core supporters say Sanders’ strength is that he’s held these progressive positions for decades.

“It’s hard not to be a bit wary of people who know how the wind is blowing and now are blowing with it,” said Norman Solomon, an author and activist who coordinates the Bernie Delegates Network — 1,200 people who served as Sanders’ delegates to the 2016 Democratic National Convention.

“Bernie is part of movements that create the wind,” Solomon said. “Bernie is not a wind sock.”

Getting personal: At times in 2016, Sanders was so on message that no matter the question, he “would respond with something about the millionaires and billionaires who are rigging the system,” Goldford said.

Now, Sanders recognizes that “Americans want to have a sense that they know who the president is, that they can trust this person to speak for who they are,” Goldford said. “The messenger is at least as important as the message. Beto O’Rourke may be all messenger and no message. And last time, Sanders was all message.”

So this time, Sanders is talking about how his family lived “paycheck to paycheck.” In a speech this month in South Carolina, he took a dig at President Trump’s privileged background by pointing out that “I did not come from a family that gave me a $200,000 allowance every year beginning at the age of 3. As I recall, my allowance was 25 cents a week, about $12 a year.”

It is a way for him to keep pace with rival candidates like Harris and Sen. Cory Booker of New Jersey, who infuse their speeches with autobiographical touches.

“He’s got to stay afloat with those guys,” said Michael Ceraso, who ran Sanders’ California campaign until shortly before the 2016 primary. “And he’s got to retail politics. Yes, he can still have his rallies, but Bernie needs to relate to the people, too.”

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli