Through the first three weeks of April, the race between Hillary Clinton and Bernie Sanders, which began collegially enough, has deteriorated.

The likeliest explanation for this turn of events was the looming primary in New York, where polls showed Clinton with a formidable lead, and arithmetic dictated that Sanders needed to far exceed expectations in order to remain a viable candidate for the Democratic presidential nomination.

At a rally in Philadelphia on April 6, Sanders questioned Clinton’s qualifications for the presidency. A couple of days later, Sanders sheepishly walked it back. The ninth Democratic primary debate on April 14 was marked by sarcasm, innuendo, and contempt. Then this past Tuesday, Clinton won the primary by an unexpectedly large 16-point margin.

It’s natural for most Democrats to hope her victory there will bring an end to what has become an unnerving stretch of the campaign. But the level of fretting over Sanders’s swipes at Clinton has been completely out of proportion to the actual damage done. It’s in the Democratic establishment’s DNA to be unsettled by intra-party warfare, and to worry about Republicans attacking their party’s eventual nominee with another Democrats’ words. But some perspective is in order. Compared to the 2008 Democratic primary—and, more proximately, to the ongoing Republican primary—Democratic infighting this year has been beanbag.

Because the Democratic Party ultimately unified behind then-Senator Barack Obama, and he went on to win a landslide victory in November, the 2008 campaign isn’t remembered eight years later for the nastiness of the Democratic primary. But the fact is, Clinton was far harder on Obama than Sanders is being on Clinton.

In a January 2008 debate, after Obama had described President Ronald Reagan as a transformative political figure, Clinton boasted that she had fought “against [Reagan’s] ideas when you were practicing law and representing your contributor, [Tony] Rezko, in his slum landlord business in inner-city Chicago.”

In February 2008, Clinton mocked Obama’s appeal to hope and change contemptuously. “I could stand up here and say, ‘Let’s just get everybody together, let’s get unified, the sky will open, the light will come down, celestial choirs will be singing, and everyone will know we should do the right thing, and the world would be perfect.’ Maybe I’ve just lived a little long, but I have no illusions about how hard this is going to be. You are not going to wave a magic wand and have the special interests disappear.” At around the same time, when Obama adopted a stump-speech line from Massachusetts Governor Deval Patrick, who had offered it up as one of Obama’s campaign chairs, Clinton called Obama’s words “change you can Xerox.”

Senior Clinton staffers undertook efforts to expand public awareness of Obama’s youthful cocaine use. They whispered to reporters that Clinton needed to stay in the race until the last primary because a career-ending videotape of Michelle Obama disparaging “whitey” might be unearthed. Clinton herself in May of 2008 cited Bobby Kennedy’s assassination on the night of the June California primary in 1968 as a reason for her to stay in the race, suggesting, perhaps unintentionally, that the Democrats needed a backup in case Obama were to be killed.

So when Jennifer Palmieri, Clinton’s communications director, suggests the candidate “set a gold standard” in 2008 “for how people who don’t end up with the nomination, who lose in that effort, should come together and help the party,” she probably doesn’t have late-stage campaign rhetoric in mind. It stands to reason that by comparison to what he actually faced, Obama would’ve preferred to have his qualifications questioned, or to have endured innuendo about his ties to Wall Street.

Even so, held up against the way Donald Trump is ingesting the writhing Republican Party in 2016, the 2008 Democratic primary was a model of civility. In February, before suggesting Trump had wet his pants (and then dropping out of the race), Marco Rubio repeatedly called Trump a “con artist.” Ted Cruz said Trump was refusing to release his tax returns in order to hide “business dealings with the mob—with the mafia.” Not only do Trump’s opponents attack him far more viciously than Sanders attacks Clinton, they often attack him more viciously than most Republicans attack Clinton.

Trump obviously isn’t a lock to win, but if Republicans hand the nomination to Cruz at the GOP convention in July, the senator will enter the general election with similar baggage. Both Rubio and Trump have called Cruz a liar in widely televised fora, and millions of Trump supporters now habitually refer to the Texas senator as Lyin’ Ted. The specter of nominating Trump or Cruz has divided the party at the highest levels, with House Speaker Paul Ryan calling on the convention delegates to nominate somebody who ran in the primary (limiting the field of potential presidential candidates to Trump, Cruz, and 15 completely underwhelming candidates), while Senate Majority Leader Mitch McConnell contends that the delegates could select “anyone,” so long as they settle on someone electable.

By contrast, polls show Democratic voters overwhelmingly satisfied with their choice of candidates, and the party is poised to host a thoroughly standard convention this summer.

Hillary Clinton is an imperfect politician, and no Democrat wants her vulnerabilities compounded by footage of Bernie Sanders questioning her qualifications. One of the most powerful tools in marketing is called third-party validation, and it is essentially this: Deploying footage or testimony of a trusted mediator—ideally someone without a stake in the product—making the same argument a company might make on its own behalf. Pepsi claiming Pepsi is better than Coca-Cola won’t sway anybody, but if four out of five blindfolded people prefer Pepsi to Coca-Cola, that conveys something powerful, and if the CEO of Coca Cola is caught on tape drinking Pepsi, well, that’s more persuasive still.

This cuts both in both positive and negative directions. Voters already expect Republicans to criticize Democrats, which robs their anti-Clinton rhetoric of persuasive power. Coming out of Sanders’s mouth, however, the attacks gain fresh credibility.

That’s why Democrats are so concerned about Sanders’s comments. But on this score, they’re actually very fortunate. Primary campaigns are frequently more damaging than the Clinton-Sanders race has been, and if the 2016 election comes down to a contest between third-party validators, Clinton will win in a landslide.