As far as the Obama backing Kamala, they did so holding their noses, they waited until Kamala had the requisite delegates.
Exactly. This was a very reluctant endorsement. And they waited a whole week? Even Pelosi and Schumer endorsed her within the day. That meant that the party was never going to put up an alternative to Kamala. Why it would take Obama a whole additional week to finally endorse her is odd.