1887 Chicago mayoral election

The Chicago mayoral election of 1887 saw Republican John A. Roche win by a landslide, receiving more than a two-thirds majority of the vote, defeating Socialist Robert S. Nelson by more than 36 points (a margin of victory which was itself greater than Nelson's vote share), in a race where the Democratic Party had failed to field a candidate.

Lack of Democratic nominee
Incumbent Democratic Mayor Carter Harrison Sr. had opted to retire. Harrison lost the backing of his party amid declining public support. Among the reasons Harrison had lost the Party's backing were his handling of the Haymarket Riot and his failure to receive the endorsement of the United Labor Party, which he had sought for a fusion ticket with the Democrats. Additionally, his handling of the Haymarket affair also harmed his standing with conservative business groups. Furthermore, his decision not to seek reelection was influenced by election scandals involving charges of fraud against some individuals. Though these charges had little to do with Harrison's own personal conduct, they posed a prospective threat to his chances of victory.

The Democratic Party nominated DeWitt Clinton Cregier, who refused their nomination. After this, and despite his declared intent to retire, they attempted to nominate Harrison, who also refused their nomination.

Campaign
Republican nominee John A. Roche ran as a fiscally conservative "law-and-order" candidate.

Roche was regarded by many Democrats to be the lesser of two evils. Behind-the-scenes, Roche received unlikely support from such Democrats as Michael Cassius McDonald. Incumbent Harrison, while not backing either candidate, dismissed many Democrats' worries about the prospect of a Nelson mayoralty, and also cautioned that a Roche election could spur the passage of additional blue laws.

Results
Roche received a roughly 27,000-vote margin-of-victory, at the time the greatest in the city's history.