The system today is a lot different with primaries everywhere and some caucuses mixed in.
Back in the 1960’s only a handful of states held primaries and only some of those had delegate selection linked to the primary vote.
The back rooms of local political power held the keys to being a presidential nominee.
Heck, the old tradition was for a candidate to not announce while his supporters lined up support in backrooms or ran him in the handful of states like New Hampshire or Wisconsin that held primaries.
The candidate would or could wait until close to the convention to announce.
Yep. This ain't our grand fathers' primary politics. She's got maybe another two weeks to step in, given the way the game is played today. I think the author is nuts.