Why did Wyatt Earp never hold the top law enforcement position in any town where he worked?

Why did Wyatt Earp never hold the top law enforcement position in any town where he worked?

Wrangler

From True West’s online forum

Wyatt entered his law career when he was elected constable of Lamar, Missouri, but that is the highest position he held in law. A “go-to-guy” like Wyatt was, more often than not, the deputy or assistant marshal. United States marshals were too busy with paperwork, while the deputies were the ones out in the field, catching the bad guys. An assistant marshal was free to pursue other interests that were far more lucrative, such as real estate speculation or gambling. Wyatt certainly did that.

He planned to run for the Cochise County Sheriff office, which was a lucrative position because the sheriff received a percentage of money collected for taxes—and there were a lot of mining and railroad interests in the county with hefty tax bills. John Behan got the honor instead, while Wyatt ended up with the girl (Josephine Sarah Marcus).