text:  Live from NPR News in Washington, I'm Janine Herbst. Multiple senior House Democrats told leaders today that President Biden should step aside as the party's presidential nominee. Many Democrats still publicly support him, even as anxiety grows within their ranks. So far, though, there have been no public calls from senators for Biden to step aside. Meanwhile, Biden's campaigning in Pennsylvania today, and as NPR's Tamara Keith reports, he appears to be answering critics with action.