It forces all the other candidates into a catch-22 where if they campaign hard in California and lose, they only make the loss look more significant, whereas if they don't, they lose massive delegates. Either way they're at an unfair disadvantage.
Well OK, I agree that an early California primary is an advantage for Harris (or, less likely, some other California candidate). And yes, obviously winning California offers a big advantage for winning the nomination. But winning the state doesn't guarantee that you'll win the nomination, as we saw in 2008. And so my point was simply that the margin there could be important, even if there's a favorite son or daughter running.
This is especially possible if there's still a large field of candidates in the race, and Harris wins California, but with less than 50% of the vote. Potentially, that could even lead to a contested convention (not likely, but not out of the question).
As for the catch-22 you talk about with regard to how hard do the candidates campaign in California....I'm assuming that none of them will have time to campaign that hard there at all. If they only have a week or less after Nevada or South Carolina to campaign in 10+ different states, including California and Texas, then there isn't much time to do anything. They would only be able to coast off of free media at that point. Even the candidates with money would struggle to be able to put enough ads on the air to make an impact.
The difference is that in 2008, there was no favored daughter California candidate. So candidates only win California by small margins (~10 points), as opposed to say a massive 20-30 point margin local candidate often get. In 2008, they really had a super tuesday with New York, New Jersey, Massachusetts, Illinois, etc. etc. a ton of states all going on the same day. Unless New York and Illinois moves up to the same day California will dominate the day.
As we saw in both 2008 and 2016, once one candidate gets even a medium-sized delegate lead, it's impossible for anyone to overtake them later.
