The confluence of events—the coronavirus, Black Lives Matter, everything Trump has done lately—has gotten Biden thinking, obviously. "I do think we've reached a point, a real inflection in American history," he told reporters. "And I don't believe it's unlike what Roosevelt was met with. […] I think we have an opportunity to make some really systemic change." He's clearly been talking to Warren.
That he's looking at a serious transformation—big systemic change—was clear from his speech Tuesday on climate change. As Mark Sumner wrote, the speech "showed that he has fully absorbed the need for a dramatic change that would reshape both America’s energy policy and the economy. In a 20-minute address that also took time to punch Donald Trump for his failures to listen to experts in dealing with COVID-19," Sumner continued, "Biden presented the outlines of a policy that's genuinely bold, and a view of how the economy and environment are related that was aimed squarely at ending the false dichotomy between good jobs and a clean future."
This is absolutely the big thinking—Roosevelt, New Deal kind of thinking—that is required to recover from what Trump has wrought. "We won't just tinker around the edges," Biden said. "We're going to make historic investments that will seize the opportunity and meet this moment in history."
That will almost certainly mean no more filibuster, because it would take a miracle for Democrats to win 13 Senate seats this November and a minor miracle for Sen. Mitch McConnell to be dislodged from his seat. As long McConnell is in the Senate and has the filibuster as a tool, we will never be able to have nice things again—none of the visions Joe Biden is clearly now having for the nation's future. It seems as though Biden is working his way to that realization, and it also seems like Warren has helped him get there.