The humility and decency it took for Biden to step off the ticket, after repeatedly saying he wouldn’t, was a surprise. Not unexpected but not guaranteed. To endorse Harris was also sensible but not foregone.
The surprising thing was how effective Harris was in the next ten hours.
She leveraged Biden’s endorsement into top-tier concurrences.
She wiped the field clear of competition.
She got big-donor pledges to calm down the finance team.
She got a huge grassroots boost on the 40K-person Zoom.