The scuttlebutt in Washington is that Vice President Joe Biden is going to throw his hat into the presidential race, which means there is at least a 50 percent chance that he will. I mean, when is the Beltway scuttlebutt ever wrong? Under different conditions, I’d guess that, if he does announce, Biden has almost no shot at winning the Democratic primary, and that his candidacy could prove a gift to Hillary Rodham Clinton.