CNN  — 

Joe Biden is in – and the knives are out.

Sen. Elizabeth Warren of Massachusetts welcomed the former vice president to the 2020 Democratic primary on Thursday by reminding voters of their old clashes over the nation’s bankruptcy laws.

“I got in that fight because (families) just didn’t have anyone and Joe Biden was on the side of the credit card companies,” Warren said after being asked about the issue following a rally in Iowa. “It’s all a matter of public record.”

The nearly two-decade-old Warren-Biden feud is, indeed, well documented. Warren has, in multiple interviews and op-eds, criticized Biden, during his time in the Senate, over his role in moving along legislation she believed would benefit big banks at the expense of working and middle-class Americans.

Warren was joined by her Senate colleague Bernie Sanders in jabbing Biden, who is poised to head up the moderate Democratic opposition to President Donald Trump in a year when progressive primary candidates have been dominating the headlines. Both of the New England senators view Biden as an ideological foe that, despite his strong early polling, could ultimately provide a useful political foil. Sanders’ campaign sent a pair of fundraising emails on Thursday, both with Biden’s name in the subject line, pushing supporters to meet the challenge ahead.

“There are a lot of candidates in this race right now. But there is only one Bernie Sanders. You know that,” said Faiz Shakir, the Vermont independent’s campaign manager, in both messages.

The call for cash in Sanders’ second email put a finer point on it, saying: “It’s a big day in the Democratic primary and we’re hoping to end it strong. Not with a fundraiser in the home of a corporate lobbyist, but with an overwhelming number of individual donations in response to today’s news. Contribute before midnight. It would mean A LOT to our campaign.”

But it is Warren and Biden who have the more colorful history. In a New York Times op-ed from 2002, titled “A Quiet Attack on Women,” Warren accused Biden of using abortion protections as political cover for his decision to support a controversial bankruptcy bill.

“Do politicians like Mr. Biden who support the bankruptcy bill believe they can give credit-card companies the right to elbow out women and children so long as they rally behind an issue like abortion?” Warren asked her in op-ed. “The message is unmistakable: On an economic issue that attracts millions of dollars of industry support, women have no real political importance.”

Biden entered the 2020 contest, after months of internal debate, with a video released early Thursday. In the first 24 hours of his third presidential campaign, Biden, who held his first fundraiser on Thursday, has sought to keep the focus on Trump, framing the coming election as a referendum on the fate of a country – saying the President’s reaction to the deadly white supremacist violence in Charlottesville, Virginia, in 2017 solidified the stakes.

“(Trump) said there were quote some ‘very fine people’ on both sides,” Biden said in his video, recalling Trump’s remarks. “With those words, the President of the United States assigned a moral equivalence between those spreading hate and those with the courage to stand against it. And in that moment, I knew the threat to this nation was unlike any I had ever seen in my lifetime.”