Well, there were a LOT of accusations. As this Vox piece from the time points out, they actually started the "Bernie Bro" attack line in 2015 https://www.vox.com/2016/2/5/10919754/bernie-bro-sexism. February, Bill Clinton said we were all sexist https://www.cbsnews.com/news/bill-clinton-accuses-bernie-sanders-supporters-berniebros-of-sexism/ and Salon did a hit piece https://slate.com/technology/2016/02/bernie-bros-are-bad-the-conversation-around-them-is-worse.html.

Her general line was that we shouldn't try to do left wing things because they won't magically solve sexism AND racism AND homophobia https://www.vox.com/2016/2/11/10976502/democratic-debate-hillary-clinton-bernie-sanders which I feel like is the TRUE heart of the "BUT YOU DIDN'T POST YOUR PRONOUNS 😭" era of neoliberal woke politics, which the neolibs are conveniently now disowning "It was all you Bernie Bros who were the social justice warriors, I have no idea what you're talking about" while Tom Suozzi curb stomps a trans 14yo child while screaming "You damnable socialists are MAKING me do this!"

Ironically even Salon at the time, noted that Hillary wasn't going to be able to win a general election accusing everyone in the DNC to the left of Dick Cheney of sexism https://www.salon.com/2016/03/25/hillary_clintons_dirty_politics_bernie_sanders_is_experiencing_the_same_nasty_tricks_that_clintons_campaign_dealt_obama_in_2008/. But true DNC water carriers like Mediaite were pushing the line still in September https://www.mediaite.com/online/why-hillary-clinton-is-right-about-bernie-supporters-and-sexism/ and the NYT was still using the line in 2019 https://www.nytimes.com/2019/01/02/us/politics/bernie-sanders-campaign-sexism.html.

Hillary was even still being a bitch about it in 2020 https://reason.com/2020/01/21/still-seething-over-2016-hillary-clinton-slams-sanders-for-sexism-sans-substance/.

The strategy was to wield identity politics as a weapon by making these false claims, eg, “It’s her turn”