Five years ago, Joe Biden was the “electability” candidate — the well-liked, moderate Democrat who promised to beat Donald Trump and had the poll numbers to back it up. The polls don’t back up Biden’s electability case anymore. In the latest New York Times/Siena College polls on Monday, he trails by 3 percentage points among likely voters in must-win Pennsylvania, while he leads by a mere 3 points in Virginia — a state he carried by 10 points four years ago. Not only does Biden trail Trump, but he also fares worse than Vice President Kamala Harris, the only other...