For the last few days on social media, Bernie Sanders supporters have been very vocal about how "unfair" the primary voting was in Arizona. Many of them seem convinced there was some sort of conspiracy against Sanders, and without that conspiracy, their candidate would have won. That's just silly.
The voting in Arizona was a mess, but it had nothing to do with any conspiracy against Sanders. It was caused by Republicans drastically cutting the number of polling stations ("to save money"). That cut in the number of voting sites forced many voters to wait in very long lines -- some of them for four hours or more. It turns out that many voting sites, especially in Maricopa County, had to handle a voter list of as many as 21,000 voters (which is ridiculous).
But this Republican display of incompetence was not aimed at any specific candidate -- although it may have been aimed at Democrats in general (since the fewest voting sites were in Hispanic areas (who are reliable Democratic, and Clinton, voters). If anything, the long lines may have hurt Clinton more because of that. Remember, both Clinton and Sanders voters had to wait in the same long lines to vote.
Sanders supporters are also complaining about Independents not being able to vote. They say huge numbers of people had registered as Democrats, but were listed as Independents. I doubt this. While a few mistakes could have been made, it is far more likely that these Independent voters had never changed their registration at all, and that they simply didn't understand how a closed primary works (expecting that any person who showed up would be allowed to vote).
The closed primary was not new, or a last-minute change. There was plenty of time for anyone who wanted to register as a Democrat to do so. I'm sure the Arizona Democratic Party welcomed anyone wanting to register as a member of their party. The Independents who couldn't vote have only themselves to blame. They knew, or should have known, the rules if they really wanted to vote -- and if they wished to remain Independents, then they had no right to vote in the Democratic Primary.
A primary is not the same as an election. It is for members of a particular party to choose their candidates for the general election. Those who are not members of that party (especially in a closed primary) cannot participate. They will get to make their choices in the general election in November, after the members of all parties put their candidate choices on the ballot.
There was NO conspiracy against Bernie Sanders in Arizona. The Democrats in Arizona simply preferred Hillary Clinton -- by a large margin.
NOTE -- There is even a movement by Sanders supporters to petition the White House to have a re-vote in Arizona (on June 7th). This is just stupid. The White House couldn't order a re-vote in Arizona, even if it wanted to do that (which I'm sure it doesn't). Arizona's public officials are solely responsible for the primary voting in that state. While these officials showed their incompetence by not providing enough voting sites, it did not invalidate the primary -- and it was not unfair to any particular candidate.