1970 United States Senate special election in Illinois

The 1970 United States Senate special election in Illinois was held on November 3, 1970, to fill the remainder of the term of Republican Everett Dirksen, who had died in office. Republican Ralph Tyler Smith had been appointed to fill the seat after Dirksen's death, and he lost the special election to Democrat Adlai Stevenson III. This election was the third consecutive time in which a United States Senate election in Illinois took place two years after a previous United States Senate election in Illinois after 1966 and 1968.

Election information
The primaries and general election coincided with those for House and state elections.

Primaries were held on March 17.

Turnout
Turnout in the primary elections was 26.28%, with a total of 1,381,147 votes cast.

Turnout during the general election was 67.43%, with 3,599,272 votes cast.

Candidates

 * Lar "America First" Daly, perennial candidate
 * William H. Rentschler, chair of the Richard Nixon 1968 presidential campaign in Illinois
 * Ralph Tyler Smith, interim Senator since 1969 and former Speaker of the Illinois House of Representatives

Campaign
Rentschler accused Smith of acquiring the Senate seat through a corrupt deal with Governor Richard Ogilvie. Smith himself denied the charge, pointing out that Ogilvie declined to support him in the primary.

Rentschler also criticized Vice President Spiro Agnew and Senator Charles Percy for endorsing Smith, arguing that party leaders should stay out of the primary race. Rentschler had previously worked on campaigns for Percy and Agnew in 1964 and 1968, respectively.

Candidates

 * Adlai Stevenson III, Illinois Treasurer and son of Adlai Stevenson II