Shortly after he began his second term in 1903, Governor DeForest Richards died in office, elevating Secretary of State Fenimore Chatterton to the Governorship and triggering a special election in 1904 to fill the balance of Richards's term.

Chatterton ran for re-election, but was defeated for renomination at the Republican convention by Bryant B. Brooks.

Aided by President Theodore Roosevelt's landslide victory over Democrat Alton B. Parker in the presidential election, Brooks overwhelmingly defeated Osborne.

As the Republican convention began on May 18, 1904, former State Representative Bryant B. Brooks was seen as having a slight edge over acting Governor Fenimore Chatterton, with the leading rumor that the Laramie County delegation held the balance of power and favored Brooks over Chatterton.

[2] Meanwhile, as the Democratic convention began on September 7, 1904, several candidates were seen as likely nominees: former Congressman and Territorial Governor John E. Osborne; former State Senator William H. Holliday, the 1894 Democratic nominee for Governor; Robert H. Homer, a former territorial legislator; and W. Dean Hays,[3] with Osborne seen as the frontrunner.