For Biden, the debate draw is a potential disaster, and an opportunity

For unknown reasons, Biden was caught flat-footed by Harris in the first debate, giving rise to new questions about his age and stamina. (I still don’t understand why Biden didn’t play his strongest card when Harris challenged him, which is his partnership with the nation’s first black president — “Kamala, Barack Obama examined every aspect of my record and chose me to be his Vice President. That should tell you all you need to know about my record and commitment on civil rights.”)

Biden also could fairly turn on Harris for appearing the day after the last debate to walk back her position on busing to something that sounded a lot like Biden’s voluntary-not-compulsory position. And he might challenge her on her on-again, off-again support of Sanders’ plan to replace the entire private health insurance system under Medicare for All.

If the front runner who appears on the stage in Detroit is strong, agile and confident in handling the incoming — and unapologetically claims the mantle as moderate — he could take a big step toward solidifying his status at the top of his pack. If not, the lamentations about his ability to go the distance will grow louder.