Bernie Sanders would have defeated Donald Trump if he were the Democratic presidential nominee in 2016 and remains the strongest candidate to prevail in 2020, Sanders’s campaign manager argues in a new memoir in which he also seeks to settle some scores with other politicians and the media.

In the provocatively titled book, “How Bernie Won,” Jeff Weaver offers an unapologetic insider’s view of the primary campaign of Sanders, the iconoclastic senator from Vermont whose bid proved far more robust than anyone imagined and is now weighing another run at age 76.

“I believe he is the strongest candidate to reclaim the White House in 2020 in this moment in history,” Weaver writes. “His authentic message of positive change and his appeal to a broad range of voters gives Democrats the best opportunity to put together the coalition that can reclaim elected office at all levels.”

“Run, Bernie, Run!” Weaver concludes his 363-page book, set to be published on May 15.

Weaver second-guesses few of the decisions that guided Sanders through his 2016 run and dismisses critics who have argued that the senator’s bid served to weaken the Democratic nominee, Hillary Clinton, in the general election.

“To the extent our campaign bears any responsibility for Trump’s victory it is that we did not defeat Hillary Clinton,” Weaver writes of campaign that won 23 nominating contests and 43 percent of the combined popular vote against Clinton.

Weaver pulls few punches when discussing the campaign’s real and perceived adversaries. They include Bill Clinton (whose presidency “tore at the fabric of the Democratic party”), then-Democratic National Committee Chairwoman Debbie Wasserman Schultz (who repeatedly “put her thumb on the scale” for Hillary Clinton) and reporters and columnists who filed unfavorable reports at key junctures in Sanders’s campaign.

Weaver, for instance, writes of the campaign being undermined in the all-important New York primary by “pathetic columnists” at The Washington Post and editorial writers at the New York Daily News — all of whom, he says, “knowingly or not, functioned in this effort as campaign proxies for Hillary Clinton.”

Weaver is kinder to Larry David, the comedian who played Sanders on a recurring basis on “Saturday Night Live.”

“Bernie thought that the Larry David portray, while over-the-top, was hilarious,” Weaver relays.

Here are a half-dozen other nuggets contained in the new book:

Sanders told Weaver from the outset that he was “running to win.” Contrary to speculation that Sanders, a self-described democratic socialist, entered the race to get a broader platform for his ideas, Weaver writes that Sanders told him that was not the case.

Weaver recounts a dinner between the two when Sanders was courting him to come on board as campaign manager.

“I told him if it was just an ‘educational’ campaign, I would be happy to max out and write nice things about him on social media, but I could not upend my life unless we were going to run to win,” Weaver writes. “ ‘Yes, I’m running to win,’ he assured me.”

Sanders was resistant to hiring a pollster for his presidential campaign and told him so when they first met. Sanders first met pollster Ben Tulchin, who would join the campaign several months later, at a boutique hotel in San Francisco in March 2015.

“Ben, explain to me why I should spend money from my supporters, who may be living off Social Security, on polling,” Weaver recounts Sanders as saying.

Weaver writes that Sanders was later convinced a pollster would be used not to craft his message but to allow the campaign to better target its resources.

It was important for Sanders, whose campaign gained momentum with large-scale rallies, to outdraw Trump in Phoenix. Weaver writes that Sanders and others on the campaign were well aware of a 4,000-plus crowd Trump drew in July 2015.

When Sanders scheduled a rally at the same venue a week later, “Bernie and all the rest of us wanted to beat him in that regard,” Weaver writes. “If our rally had the unintended consequence of knocking some air out of his balloon, all the better.”

Sanders’s rally drew an estimated crowd of 11,000.

Sanders was heavily prepared for the first Democratic debate in Las Vegas, but his most memorable line — about Clinton’s emails — was unrehearsed. “That was all Bernie,” Weaver writes.

During the October 2015 debate, Sanders received a standing ovation for his response to the ongoing controversy about Clinton’s use of a private email server while secretary of state.

“Let me say something that may not be great in politics, but I think the secretary is right,” Sanders said. “I think the American people are sick and tired of hearing about your damn emails.”

The Sanders campaign unsuccessfully sought to strike a deal with Maryland Gov. Martin O’Malley (D) in the Iowa caucuses. Weaver writes that he reached out to O’Malley’s campaign manager in advance of the first nominating contest.

The goal was to agree to a swap of supporters in precincts where, under the complicated caucus rules, it could accrue to the benefit of one or the other campaign. Sanders had the most to gain, but Weaver also argued there was also a benefit for O’Malley.

If Sanders beat Clinton in Iowa, she would be considerably weakened heading into New Hampshire, allowing O’Malley more of an opportunity to play there, the reasoning went.

“So you are asking me to help you win today so that I have a chance to win tomorrow?” Weaver quotes O’Malley campaign manager Dave Hamrick asking him.

In the end, Weaver says, O’Malley decided against a deal. O’Malley dropped out after Iowa.

Sanders’s campaign hoped an upset victory in the New York primary would sow doubts about Clinton among Democratic superdelegates. Weaver quotes campaign consultant Tad Devine sizing up the importance of the contest.

“If we can beat her in her home state it is really going to shake people’s confidence in her, and then we will see a lot of those superdelegates start to take a second look at the race,” Weaver quotes Devine as saying.

Wooing superdelegates — elected officials and other party insiders who have a say in the nominating process and are not bound by their state’s results — proved a major hurdle for Sanders that he never surmounted.

Clinton prevailed in New York primary with 57 percent of the vote.

Relationships were not exactly warm and fuzzy between the Sanders campaign and several Democratic establishment politicians. In the book, Weaver takes shots at Democrats who worked at cross purposes with his campaign.

Bill Clinton comes in for some of the harshest criticism, including for his efforts to find a more centrist path for the party during his tenure as president.

“Bill Clinton’s administration represented an aberration in the historical trajectory of the Democratic party toward more inclusion, more economic equality and broader and broader opportunity,” Weaver writes early in the book.

Others who draw fire for their actions during the campaign include then-Vermont Gov. Peter Shumlin, who was among several Democratic politicians from the state who endorsed Clinton on the day of Sanders’s official announcement as a candidate.

“Shumlin’s endorsement of Clinton was a particularly tasteless move,” Weaver writes, noting that Sanders had campaigned for him during the 2014 governor’s race. “Without Bernie, he would have lost. And everyone including Shumlin knew it.”

Weaver also takes aim at Connecticut Gov. Dannel Malloy (D), among the Clinton supporters who sought to make the case that Sanders was weaker than Clinton on gun control. Weaver highlights a decision by the Malloy administration to offer loans to gun manufacturers in his state.

“He talked about gun control out of one side of his mouth while providing state dollars to the gun industry out of the other,” Weaver writes,” accusing Malloy of “hypocrisy.”

Weaver offers several glimpses of Jane Sanders, the candidate’s wife. Weaver writes that he, Bernie and Jane Sanders were sitting in an idling Jeep Cherokee ahead of Sanders’s official announcement in Burlington.

“It was Jane who pointed out the environmental impact of sitting in an idling car,” Weaver writes. “Her point was well taken, so we got out.”