There has been much discussion about whether votes in this next election will be counted securely.
Every state has rules about what poll observers can do at the polls and how votes can be challenged. Here are the rules for your state:
Arizona The county chairman of each party may designate a party agent or representative and alternates for a polling place in the precinct who may act as challengers for the party which appointed him. At each voting place, one challenger for each political party may be present. (Ariz. Rev. Stat. § 16-590)
Any qualified elector of the county may orally challenge a person offering to vote as not qualified under section 16-121.01 or on the ground that the person has voted before at that election. (Ariz. Rev. Stat. § 16-591)