No. of Recommendations: 1
Is it really a "national campaign"? The election will be decided by about 100,000 voters spread across 5 or 6 swing states. Big money Democratic donors will surely be able to get enough money and resources to whichever candidate replaces Biden.
I mean "national campaign" in the sense that the campaign has to cover a lot more than a single state. Someone like Whitmer or Shapiro would have a very solid organization in their home states - but they've never had occasion or need to hire a campaign staff in Arizona or Nevada or Georgia or what have you. There's only 5 or 6 swing states, it's true - but there are also a bunch of "leans blue" states that the Democrats still have to staff up and run a competent campaign to make sure that the state ends up where it's likely to end up. So while the Democratic nominee probably isn't going to lose Minnesota or Colorado or New Mexico, they still need to run a campaign there.
So if Biden were to drop out in the next week or so and the party coalesced around Harris, she'd probably just end up using the existing campaign staff in Nevada and Arizona and Georgia and Michigan or what have you. The organization would remain in place, no need to build anything new - so the campaign manager and other national staff can concentrate on running the campaign rather than taking a few weeks to hire people all around the country.
That's not likely if there's a free-for-all convention. Not only does the choosing of the nominee get delayed for another month or so (so those staff members might find other things to do rather than wait around), but the various individuals jockeying for the nod will be competing in all those states for delegates and staff. Deals for support will be cut, alliances will be formed, egos bruised and oxen gored. Making it less likely that the local politicos that are making up the current Biden-Harris campaign will necessarily be the ones that the Newsom-Pritzger or Whitmer-Shapiro tickets can live with (and vice versa).