Democratic candidates bail on Biden?

Can a candidate who is leading the field by 12 points be weak? That’s the question of Joe Biden’s run for the Democratic presidential nomination.

The fact is, Biden’s campaign is showing signs of weakness. So is the candidate himself. And doing push-ups, as Biden suggested he might do to show up President Trump, won’t make him any stronger.

In mid-May, Biden led the sprawling Democratic field by 26 …