After Joe Biden’s campaign Tuesday night released an online video accusing the campaign of Sen. Bernie Sanders of unleashing a “barrage of negative attacks” and “not telling the truth”  about the former vice president’s record on Social Security, the hashtag #TelltheTruthJoe began trending on social media and Sanders himself shot back by saying: “Let’s be honest, Joe. One of us fought for decades to cut Social Security, and one of us didn’t. But don’t take it from me. Take it from you.”

Characterizing the Biden campaign video as “the first negative ad of the 2020 Democratic primary,” Sanders campaign manager Faiz Shakir, in a statement, said it was important for people to understand why it was being released now.

Biden, said Shakir, is “trying to distort his decades-long record of proposing and voting for cuts to Social Security benefits for millions of people.” According to Shakir, the well-documented history shows that “Biden is no defender of Social Security, and a negative ad won’t help him outrun his record.”

To again bolster their case, the Sanders campaign released detailed fact sheet (pdf) as well as a new video of their own detailing Biden’s long history of calling for Social Security cuts and espousing his willingness—across numerous decades in Congress and during his time in the White House with President Barack Obama—to work with Republicans on the effort. While Briahna Joy Gray, national press secretary for the campaign, noted early Wednesday morning the video had received over 1 million views in a matter of hours since it was released, as of this writing the figure was much closer to 2 million:

Supporters of Sanders, including author and activist Naomi Klein, tried to make clear that the Sanders campaign video is not an attack ad against Biden but a serious effort to set the record straight about Biden’s 40-year record of being will to freeze, trim back, or cut spending for Social Security.

“Truth time folks, on the issues,” Klein tweeted, along with the campaign video, Wednesday morning. “This is not a personal attack (so don’t even start) but the issue is damn well personal for millions of people who depend on social security to live.”

Warren Gunnels, senior policy advisor to Sanders and known as “chief of receipts,” tweeted:

While New York Times columnist Paul Krugman demanded the Sanders campaign apologize for circulating a previous video highlighting Biden’s willingness to join with Republicans to cut social programs—a video which the former vice president over the weekend falsely claimed was “doctored”—Nancy Altman, president of Social Security Works, a non-profit group that advocates for defending and strengthening the program, shot back by saying: “The truth is that the clip is in no way doctored.”