President Biden riled voters during a series of campaign stops in Pennsylvania on Sunday, attempting to shake off concerns among some Democrats that he isn’t up for a second term. “Dark Brandon is coming back,” he joked to one supporter in Harrisburg who asked him about the meme, one that developed into a unifying force to fight off concerns about Biden’s age early in his campaign. While he faces increasing calls from members of Congress to leave the campaign after a faltering debate performance last month, Biden said he hasn’t seen the same response from voters.