Political Consultant Joe Mercurio emailed around a bit of research on past blowouts in Mayoral elections. Turns out John Purroy Mitchell is the man to beat, if you forgive him for running before women got the vote.
For Mayor Mike Bloomberg to set the record for biggest modern Republican win in a New York City mayor race, he has to beat the Rudy Giuliani v Ruth Messinger contest in 1997, when Mayor Giuliani (R-L) received 783,815 and Messinger (D) 549,335 for a spread of 234,480 votes, 17.3% out of 1,353,770 votes cast. (Note: most mayor elections have more than the two main contenders.)
To top that election, you have to go all the way back to 1937 when Mayor Fiorello H. LaGuardia (R), in his second race, romped Jeremiah T. Mahoney (D) 1,344,630 to 890,756 for a huge 453,874 vote spread, fully 19.7% out of 2,300,220 votes cast. (Note: LaGuardia received more votes than Giuliani and Messinger combined; and the spread was just under the total turnout for this year’s Democratic Primary.)
If you go back to the 1913 election, there is a larger spread in percent, but the city had a much smaller voting population. Democrat John Purroy Mitchel won on the Fusion line with 358,217 votes to 233,919 for Edward E. McCall on the Democratic line. A spread of 124,298 votes, 19.8% out of 627,127 votes cast. (Note: women did not get the vote until 1920, and the city’s population in the 1910 census was only 4,766,883 people.)
Since women had the vote, the lowest turnout in a mayoral General Election was Edward I. Koch’s (D) third term win against Carol Bellamy (L) and Diane McGrath (R) with 1,106,762 votes cast; and the highest turnout was John V. Lindsay’s (R-L) defeat of Abraham D. Beame (D) (later elected mayor in 1973) with 2,652,451 votes cast.
NOTE: This version includes a correction to the Beame reference.