Why isn't "I've been preparing for this moment for the last 4 years" Newsom or Whitmer not an option? Is it strictly name recognition? Or is it Trump gaining the "incumbent advantage"?
They want clean slates to run in 2028. They step in and lose to Trump and their national political careers are pretty much over, even if the Dem electorate forgives them for essentially ousting Biden
Besides "we're bypassing the sitting VP"- it's July. Any non-Harris candidates start with 0 dollars and 0 infrastructure that they need to build in 4 months, besides a rush vetting nationally by a huge percentage of voters who don't know who either of them are.