The mood among Washington Democrats is grim. Understanding that Joe Biden is headed toward defeat, they’ve also come to the conclusion that there’s nothing they can do about it — that unless Biden willingly steps aside, their side is doomed to failure. Three senators — including Jon Tester and Sherrod Brown, fighting to hold on in competitive elections this fall — said this out loud to their colleagues behind closed doors. The third, Michael Bennet of Colorado, was willing to say it publicly on CNN, even invoking the prospect of a “landslide” that results in…The mood among Washington Democrats is...