It seems to me that if the ACC is raided, or ESPN declines contract renewal, or FSU/Clemson wins lawsuit ...
If in any of many many ways, the ACC is diminished ...

That Cal and Stanford might want back into the PAC.

RIGHT NOW, that ACC is way way better than the PAC for Stanford and Cal.
But if the ACC loses the ESPN contract, and loses 4 or 6 top schools, then there might not be as big a difference, and it might be worth it CalFord to save on travel across the board.

That depends A TON on what happens to the ACC. If the ACC loses FSU and Clemson, then CalFord should probably stay. If ACC loses FSU, Clemson, NC, Miami, and maybe VT and GT, then it's probably about equal for CalFord (and they probably stay ACC just to NOT be perceived as going back), If the ACC loses FSU, Clemson and a bunch more teams, maybe even some to BigXII, then I think CalFord goes back.