A former top Hillary Clinton campaign staffer, who was most recently the head of a far-left judicial advocacy group behind the court-packing push and tweeted in support of defunding the police, is being tapped by the Biden campaign to lead communications for Vice President Harris. Sheila Nix, Harris’ campaign chief of staff, said Fallon brings an array of understanding on matters important to Americans while touting his experience.”Brian brings a wealth of expertise and knowledge on the issues that matter most to the American people,” Nix said in a statement to the Washington Post, which first reported the hire. “We’re thrilled to have him join the team, and know he will be a huge asset to reelecting President Biden and Vice President Harris.”BILL CLINTON RIPPED HILLARY’S CAMPAIGN AS NOT BEING ABLE TO SELL ‘P—- ON A TROOP TRAIN,’ NEW BOOK SAYS Brian Fallon, national press secretary for the 2016 presidential candidate Hillary Clinton campaign, speaks during a Bloomberg Politics interview in Manchester, New Hampshire, Feb. 4, 2016. (Victor J. Blue/Bloomberg via Getty Images)Fallon, who will reportedly begin in his new role next month, previously served as the national press secretary for Hillary Clinton’s failed 2016 campaign. He’s spent the past several years leading Demand Justice, a progressive judicial advocacy organization.Fallon’s group started with efforts to discredit Republican judicial picks while backing Democratic nominees and has since morphed into more advocacy-based endeavors, such as expanding the Supreme Court, or “court packing,” along with the lower courts.During a 2020 podcast episode, Fallon explained why his organization started leaning into court packing, citing advice from left-wing activist Elie Mystal, who has said he would push for the addition of 10 new Supreme Court Justices so that there are 19 total. He has also called the Constitution “trash.” Elie Mystal, right, has repeatedly called for the Supreme Court to be expanded. (Getty Images)Fallon said that Mystal “was one of the leading voices calling for ideas like reforming the Supreme Court.” He went on to say that if people like Mystal, who “are on the inside,” who write for “elite audiences like this are willing to call it out,” Demand Justice “should be willing to try to organize by it.””So that’s when I first got acquainted with Elie, and we did an event together in December of 2018 and took the house down with storytelling that is on display here, right now, and that’s when we decided to sort of lean in on that issue,” he said.Demand Justice met with multiple Democratic senators in 2021 to discuss legislation proposing adding 4 seats to the Supreme Court. Several of Biden’s top aides have had connections to Demand Justice. Former White House press secretary Jen Psaki served as a “communications consultant” for the group. Paige Herwig, Biden’s point person on judicial nominations, also worked for the group before joining the administration. Christopher Kang, another co-founder of the group, served in the Obama-Biden administration, where he served as Obama’s deputy counsel and special assistant for legislative affairs.’DEEP, DEEP TROUBLE’: DEMS REPORTEDLY BRINGING IN HILLARY CLINTON TO HELP WITH BIDEN’S RE-ELECTION President Biden and Vice President Kamala Harris. (Getty Images)In addition to being an advocate for court packing, Fallon took to Twitter in 2020 to voice his support for the movement to defund police.During his time with Demand Justice, Fallon also enjoyed close access to the Democracy Alliance, a group of wealthy Democrat donors co-founded by George Soros that helps drive the progressive agenda. In 2018, Fallon mingled at an Atlanta gathering of the donor club, where he was in attendance to promote his group before its launch, the Washington Free Beacon previously reported.While Demand Justice’s complete list of donors is unknown, Soros is among its earliest-known backers. CLICK HERE TO GET THE FOX NEWS APThe Open Society Policy Center, the advocacy arm in Soros’ nonprofit network, donated $2.5 million to Demand Justice around the time of its inception in 2018. Since then, the policy center has provided $5.75 million more to support the group, according to its grant database.The Biden campaign did not immediately respond to Fox News Digital’s request for comment. Joe Schoffstall is a politics producer/reporter for Fox News Digital. Story tips can be sent to Joe.Schoffstall@Fox.com and on Twitter: @joeschoffstall