Debate with the sound turned off

Don't overthink this. Biden looked like a president.

This was an audition. 

We have seen Trump. His self congratulation seems odd, misplaced, and dishonest. He is unreliable. He is trying to sell us something. That's Trump.

This was a chance to see Biden, the alternative. 

This was the look in the first half hour

I watched the whole debate. I lost interest. If I lost interest then I am guessing most people lost interest.  I consider 90% of the impact of the debate to have been the first half hour.

Biden looked like a competent president. The six-foot distance between them told viewers a second clear message. Biden was the president and Sanders was on the outside, looking in and across a divide, pointing out problems. The staging confirms the placement of Biden in the Democratic Party. He is an outside consultant and critic. Sanders chose to be an Independent, who caucuses with Democrats, rather than a Democrat. He brands himself a Democratic Socialist rather than a "True Democrat."

But Biden made three big errors, in my opinion.  

One was the pose he is showing here, leaning on the lectern, looking down. It projects either weariness or guilt, neither of which are good. Especially after the first half hour, he slipped into this pose while Sanders spoke. Terrible, terrible body language.

A second is that he engaged Sanders in defense and explanation of past votes. His strongest argument would have been to admit gracefully that the world changes, good ideas evolve, and keep insisting that the only relevant thing is the present and future, not the past. Dismiss the past. Breezily say that in the context of the time it was exactly right but then decisively pivot to the future. The more Biden talks about the past the more his long tenure projects a backward orientation rather than a future one.

Biden might have shown some generosity, and instead of criticizing Sanders for his votes protecting gun manufacturers, he might have said he understands that the vote was long in the past and he understands that Sanders represented a rural state and that he accepts Sanders evolution on the subject. Having shown that he forgives the past and is oriented to the future, then Sanders' criticism of Biden's past would be recast as petulant and irrelevant. Biden briefly hit that note, but most of the time he and Sanders bickered over past votes. 

Fortunately for both of them, it was pointless and therefore boring.

The third is that this was an opportunity for agreement, not disagreement. Biden's job was to assure the public that he was the bridge uniting the left and center of American politics. He could have repeatedly said something along the lines of, "My friend the Senator is right to have raised this issue and put it in the center of American politics and we agree on the goal of . . ." There was very little of that. Instead, they bickered over differences.

This third point was boring but likely not pointless. Sanders' supporters would hear the message loud and clear that Biden and Sanders disagree.

Bottom line:  

1. Biden looked competent and presidential, especially in the first half hour.  Good enough. Better than Trump.

2. Biden did not build the bridge to the progressives.  Sanders' supporters won't be mollified.