[Ed. – Even the Left is unable to ignore this fiasco.]
Here is a science-fiction scenario: Imagine a strange new virus that incapacitates everybody below the age of 75. The virus wipes out the entire political leadership, except one old man, who has survived on account of his age, but may also be too old to handle the awesome task before him.
Now suppose — and I am not certain this is the case, but just suppose — that this is happening to the Democratic presidential campaign. The virus is Twitter, and the old man is (duh) Joe Biden.
In the aftermath of the 2016 elections, an exotic political theory promoted by the party’s most left-wing flank suddenly gained wide circulation. The appeal of Bernie Sanders proved Democrats were ready to embrace socialism, or at least something close to it; and Donald Trump’s election proved a nominee with extreme positions could still win.