Wyatt Earp, of course, was a Republican.
Yep. The doin's in Tombstone were as much political posturing as anything. Earp vs. Behan = Republican vs. Democrat which extended to the town political structure vs. the "Cow-boys".
The 1880 elections in Pima County had Wyatt Earp backing Bob Paul (R) for County Sheriff over Charlie Shibell (D) who was the incumbent, even though Earp was Shibell's Tombstone deputy. The vote was close (mostly because of evident voter fraud in outlying areas) but Shibell won. Paul contested and later won his appeal to become Sheriff.
Meanwhile, a new county, Cochise, was being carved out of Eastern portions of Pima County. Democrats in the State Legislature were able to get John Behan awarded the position of Cochise County Sheriff (from Republican appointed Governor John Fremont). Earp had been close to Behan and thought Behan would award him the position of Undersheriff. But Behan awarded that plum to friend Harry Woods, an Earp antagonist. This was the beginning of the Earp/Behan feud (not to mention the issue of Josephine Marcus).