I did think New Hampshire was missing from the list but I didn't follow up on it. Thanks for pointing it out!
I just Googled it and found (on
Wikipedia) the reason it's not on the list:
It is not a closed primary, in which votes can be cast in a party primary only by people registered with that party, in that state. Undeclared votersthose not registered with any partycan vote in either party primary. However, it does not meet a common definition of an open primary, because people registered as Republican or Democratic on voting day cannot cast ballots in the primary of the other party.
Edited by kjsimons, : Found the answer why NH is not on the list.