To the extent we're able to tell (and we probably can't) it sure looks like the *debate* shift in the polls was very modest but the post-debate Dem and media freak-out shift in the polls may be somewhat larger. Still small enough that all of it could easily dissipate quickly. Or not! At any rate...
The polls aren't going to tell Biden and the Dems what to do. All comes down to whether the debate was a bad night (that looked worse because of superficial stuff) or if he's really no longer up to the job. (And any Dems with solid evidence of the latter should be making it public right now).
As I said, hard to separate. But the one-day polls seem (*seem*) to show less of an effect than those taken later -- which are capturing both the debate and the freak-out effect.
But absolutely it's hard to know.
