In 2016, then Democratic presidential nominee Hillary Clinton, left, and US Sen. Bernie Sanders (I-VT) went on the campaign trail together.

Former Hillary Clinton aides want the American public to know that they’re still mad about Bernie Sanders.

In the past week, a number of Clinton staffers have gone to the press, both publicly and anonymously, to air their frustrations about the Vermont senator, who launched his 2020 presidential bid late last month.

Politico reported former aides slamming Sanders for demanding a private jet to stump for Clinton in the general election. Talking Points Memo said top Clinton staffers called to say they think Sanders allowed the “Bernie Bros” — the trope used to describe a young, white, male, extremely online Sanders supporter — to sow division within the Democratic party. Top Clinton aides want the media to hit his past record on gun control and same-sex marriage. A lot of former aides really just want to complain about the loud, angry tone Sanders uses when he rants about corporate greed.

At the core of their frustrations is a belief that Clinton beat Sanders fair and square and that Sanders was a sore loser. These attacks are their way of warning the American public it could happen again, leaving a divided Democratic party in the general election against Trump.

“I think we are all just scarred by 2016 at large and would like to prevent that again,” one former Clinton staffer said of the attacks against Sanders.

These former Clinton aides aren’t tearing apart Sanders’s current policy agenda (probably because most major Democratic candidates have essentially adopted it). They’re just saying, here’s a bunch of dirt we had and we would like Sanders to have to deal with if he’s going to run again.

“I’m not necessarily an anti-Bernie guy, especially not when it comes to his policies,” another ex-Clinton staffer, who worked on her campaign’s research team, said. “But he has this self-righteous attitude to himself. If you are not with him you are against him, and I think we are seeing that kind of behavior in the White House, to be honest. And that style is not what we need.”

But in the machinations of the Sanders-Clinton rivalry, in which both camps purport each others’ teams engaged in nefarious tactics to ultimately deny Democrats the White House, one statistic is often forgotten: as best as we can tell, more Sanders primary supporters voted for Clinton in the general election than Clinton supporters voted for Barack Obama in 2008.

And while Clinton’s aides say they are trying to even the playing field in 2020, this relitigation of 2016 is doing more to reopen past wounds than heal them.

Why the relitigation of 2016 will never end

The 2016 primary was bitter.

Clinton had been preparing for her moment for eight years through Barack Obama’s presidency. Then Sanders came close to winning in Iowa and handily won the New Hampshire primary, throwing Clinton’s presumptive nomination into question. He mounted a long and serious challenge, staying in the race through every single primary — even after it was mathematically impossible for him to clinch the nomination.

In the end, Sanders lost because Clinton won 34 primary contests, whereas Sanders only won 23, giving Clinton a 3 million popular vote lead and the Democratic nomination.

But throughout it all, a frustration grew over the fairness of the 2016 election. It’s understandable: Democrats were dealt a devastating blow in 2016, and everyone involved feels slighted. Clinton even wrote an entire book about it, where Sanders landed among the factors she has come to blame for her loss.

The bitterness hasn’t gone away.

Sanders’s supporters maintain the 2016 primary was rigged; Clinton was the establishment candidate, lifted by the entirety of the Democratic Party apparatus, from the way the Democratic National Committee scheduled debates to fundraising — and besides, she had the support of the Party’s superdelegates before the primaries even began.

This all came to a head in July 2016, when the DNC’s then-chair Debbie Wasserman Schultz was forced to abruptly resign just as the party’s nominating convention began. The central issue was leaked emails (now believed to be hacked by Russians) showed Democratic leaders disliked Sanders. After the election, Donna Brazile, who was appointed to replace Schultz, revealed that the DNC, deeply in debt at the start of the 2016 cycle, had struck a deal with Clinton in 2015, essentially trading some of its autonomy for Clinton’s fundraising help. To Sanders supporters, this was all evidence that the primary was rigged from the beginning.

But Clinton’s team says Sanders was just a sore loser. Sanders didn’t concede the primaries even when there was no path to the nomination, saying he wanted to see his “political revolution” to the end. His campaign manager told Bloomberg Politics at the time that their campaign “would like to get to a place where we could very actively support the nominee,” hinting that Clinton would first have to adopt a more progressive vision.

Sanders endorsed Clinton in July of 2016. But tensions remained. Recently asked whether he would seek advice from Clinton’s team, Sanders said “I think not,” giving Clinton surrogates more fodder to say Sanders was never on their side.

“The one difference between Clinton people and Bernie people is we would vote for Bernie if he got the nomination,” the former Clinton research staffer said. Exit polling tells a different story; there wasn’t a massive Bernie Bro defection in 2016.

“This is a little anecdotal — I just heard from the Bernie side,” the Clinton staffer clarified.

Clinton’s aides want Sanders to be put through the media wringer

Ahead of Sanders’s 2020 announcement, Democratic strategist Zac Petkanas, a former senior aide to Hillary Clinton, penned an op-ed for NBC News warning Sanders of a deluge of negative media coverage to come. He gave Sanders a taste of what they should expect, blasting his voting record on gun control, immigration, and same-sex marriage.

Petkanas writes:

While in 2016 he cultivated a reputation around popular left-wing positions like Medicare-for-All and free college, the broader embrace of those issues in the Democratic party means that his opponents in a second presidential campaign will inevitably address his lesser-known and decidedly less progressive record on the issues that cut directly against his liberal brand.

Petkanas gets at the core of these Clinton attacks against Sanders — a widespread belief that Clinton was unfairly targeted in the press, torn to pieces on every vote, posture, and position, whereas Sanders got a pass.

“We just want every candidate to be treated the same. And we don’t want some people to be media darlings,” one of the former Clinton campaign aides told Vox, citing Sanders’s record with immigration and dismissal of identity politics.

“He’s coming into this new race with the same messaging, the same team,” another Clinton aide said. “He hasn’t adapted the messaging to the post-loss world that we live in. Democratic socialism is more popular than ever, but the broader message around institutional racism, he’s still in this ‘identity politics doesn’t matter’ ... saying things that don’t resonate with a lot of people who don’t share his privilege as a cis white man in politics.”

The generous reading of the Clintonite argument is that media coverage did seem like it was unfair. A post-2016 election study from Harvard’s Shorenstein Center found, “Clinton’s alleged scandals accounted for 16 percent of her coverage — four times the amount of press attention paid to Trump’s treatment of women and sixteen times the amount of news coverage given to Clinton’s most heavily covered policy position.”

But Sanders and his supporters have their own media critique to make. They pointed out the media also wasn’t focusing on the senator’s movement, calling it a “Bernie Blackout.” A June 2016 study from Harvard’s Shorenstein Center found that Sanders’s media coverage did indeed lag:

By summer, Sanders had emerged as Clinton’s leading competitor but, even then, his coverage lagged. Not until the pre-primary debates did his coverage begin to pick up, though not at a rate close to what he needed to compensate for the early part of the year. Five Republican contenders — Trump, Bush, Cruz, Rubio, and Carson — each had more news coverage than Sanders during the invisible primary. Clinton got three times more coverage than he did.

It’s important to note that Sanders, like these Clinton aides, has already said he will support whoever wins the Democratic nomination.

But for now, it seems, the Clinton world’s bitterness will continue to fuel the news cycle.