December 9 was the deadline for candidates to file in the Arizona Democratic presidential primary. Eighteen candidates filed. They merely had to show that they were on the ballot in at least two other states.
Here is the list. There will be no Libertarian presidential primary and no Republican presidential primary, because those parties told the Secretary of State they don’t want a presidential primary.
The list includes the links to the applications. One qualification in Arizona is qualifying in two other states.
Mark Ellinger paid the $1000 in New Hampshire, qualified in California based on qualifying in New Hampshire, then qualified in Arizona based on California and New Hampshire.