>>>Arpaio did endorse and help get Janet Napolitano elected as Governor in 2002<<<
Wrong.
Arpaio is a Republican. In 2002 Arpaio endorsed Betsey Bayless for Governor in the Republican primary.
http://www.azcentral.com/news/articles/2002/11/17/20021117arpaiocandidates-CR.html
He didn’t endorse Democrat Napolitano or anyone else for Governor in the 2002 General Election.
http://www.eastvalleytribune.com/article_d5955439-ab3c-592e-9fc6-dad0f14504e1.html
To be accurate, Arpaio did appear in an ad that Napolitano touted as an endorsement. Arpaio denies that was his intent.
As for Arpaio endorsing Romney in 2008, he endorsed him over McCain. In 2010 Arpaio endorsed J.D. Hayworth over McCain for Senate. I think it’s safe to say Sheriff Joe doesn’t like McCain.