Since losing the most winnable presidential election in modern American history, Hillary Clinton has, among other things: given a series of high-profile speeches, joined Gov. Cuomo at his public unveiling of tuition-free college, refused to rule out a run for mayor of New York and issued an online video message exhorting fellow Democrats to fight on in her name.

“The challenges we face,” she said, “as a country and a party, are real.”

Clearly, Hillary still sees herself as the leader of the Democratic Party. And why shouldn’t she? Democrats have been locked in an abusive relationship with the Clintons for decades, enabling, explaining, convincing themselves that next time will be different. Party faithful hew to Hillary’s excuses for losing to Donald Trump: It’s James Comey’s fault, plus the Russians, white supremacists, misogynists, the deplorables and immobilized millennials, among other things.

Her losses in 2008 and 2016 have been framed as things that happened to Hillary — not one, but two Black Swan events that stymied her historic destiny.

How is it that Democrats have fealty here, let alone sympathy? How is it that Hillary routinely walks into standing ovations at Broadway theaters? Where is the realization that Hillary is to blame or the rational rejection of a two-time loser?

Any debate about what happened last November ends with Tuesday’s publication of “Shattered: Inside Hillary Clinton’s Doomed Campaign.” Journalists Jonathan Allen and Amie Parnes spent the past two years talking to Hillary’s most trusted advisers, and what emerges is damning.

Every mistake made in her 2008 run was compounded in 2016: the paranoia, the staff infighting, the underestimation of the intra-party wild card, the self-righteousness, the failure to connect with average voters, the belief that because it was her turn the presidency would be hers. It’s “Groundhog Day” with global consequences.

According to “Shattered,” after a year spent crisscrossing the country, “Hillary still couldn’t figure out why Americans were so angry.” Jon Favreau, Obama’s favorite speechwriter, lasted with Hillary mere weeks, quitting before she even formally announced.

She has no clear reason for running, Favreau told her staff. She has no clear vision for the country and can’t answer two simple questions: Why her, and why now?

By late 2015, Hillary told an aide she still had no idea what voters needed. “I’m really trying to put my finger on what the electorate, the Democratic primary electorate, the broader electorate is thinking and feeling right now.”

By then, the US economy had been decimated for seven years. Unemployment was stagnant, with 7.5 million Americans without work. One of every 122 homes had been foreclosed. More than 33,000 Americans died as a result of the opioid epidemic. An average of 20 veterans committed suicide per day. There was no shortage of issues.

Where is the realization that Hillary is to blame or the rational rejection of a two-time loser?

Similarly, Hillary didn’t get why Bernie Sanders was resonating. Her worst defenses kicked in, fertilized by her top aides. “From the Clinton campaign’s perspective,” the authors write, Bernie “was getting an even easier ride from the media than Obama had in 2008.”

Hillary’s Twitter feed indicates that she’s learned nothing. She posts about social issues and identity politics through the prism of her loss. She remains woefully out of touch and she still doesn’t get what her husband did way back in 1992: It’s the economy, stupid.

Unless deprived of oxygen, Hillary and her cohort will press on, further retarding party progress. Stars such as Elizabeth Warren and Kirsten Gillibrand are fighting for column inches, airtime and party dominance as the Clintons stubbornly remain.

Two weeks ago, reports surfaced that Huma Abedin, long viewed by Hillary’s top aides as a major liability, is shopping a $2 million tell-all. Given that the book has Hillary’s blessing, and that Abedin’s husband, Anthony Weiner, remains under federal investigation for child pornography — and that she’s still married to Anthony Weiner — who really thinks she’s going to spill anything? It smacks of Abedin’s environment: another grubby Clinton-style cash grab, promising something she’ll never deliver.

Chelsea Clinton, meanwhile, is reportedly being groomed for a congressional seat and this week appeared on the cover of Variety as a “Woman of Power.” She’s never looked happier, and she’s never attempted to look so hip, outfitted in jeans, a white T-shirt and black leather jacket. Who could she be hoping to reach?

“This is not the time to be silent or stay on the sidelines,” Chelsea said. In true Clintonian mixed-messaging, she’s ruling out a run for office while continuing to raise her profile, offering policy-free platitudes to heartbroken Dems. “Talk about what’s really at risk in this moment,” she said. “Raise your voice and help others raise their voices.”

It’s a version of her mother’s intransigence, the refusal to admit voters have rejected this brand twice and to act with resultant humility. According to “Shattered,” Hillary’s repeated refusal to apologize for anything — most notably the use of her private server while secretary of state — was one of her most frustrating faults. Her closest aides kept pushing early on for a sincere apology to the American people, but Hillary remained defiant.

In fact, the only time her aides heard Hillary apologize was on election night, after her loss was indisputable. Even then, President Obama had to urge her to concede. “Mr. President,” Hillary said, “I’m sorry.”

It’s an apology Hillary owes her supporters, who have stuck through two ostensible “sure-thing” runs for president. And then Hillary and the would-be Clinton dynasty should do the right thing and just go — before the party, like the weary American electorate, is forced to show them the door.