text:  From NPR and WBR, I'm Scott Tong in Washington, D.C. And I'm Lisa Mullins in Boston. This is Here and Now. President Biden sent a letter to congressional Democrats today. He vowed to stay in the race to the finish and to beat Donald Trump. Calls for Biden to end his campaign have not eased up since his halting performance in the debate last month, but Biden has ignored them. Earlier today, he called into MSNBC's Morning Joe program. Biden said his critics have counted him out before.