Why do some states have September primaries?

[bluestateguy]

I hate September primary elections. Primaries should be over by June. In a situation where you have a divisive primary, both candidates are hacking away at each other for months, draining their campaign bank accounts and complicating their efforts to unite the party and win in November. September should be general election season.

[Ms. Toad]

1. On the other hand,

We've had candidates hacking away at the opposing party candidates since May (our primary), rather than just starting. I'm very tired of it already, with 2 months go go. Personally, I prefer the shortened overall period of nastiness which late primaries create (and in our case, I would have preferred that Blackwell, Petro, and Montgomery continue to hack at each other through September rather than giving Blackwell so much time to recover from the drubbing he was taking during the primaries).