The 1972 United States Senate election in Illinois took place on November 7, 1972.[1] Incumbent Republican United States Senator Charles H. Percy sought re-election to the United States Senate. Percy was opposed by Democratic nominee Roman Pucinski, a United States Congressman from Illinois's 11th congressional district, whom he was able to defeat handily to win a second term. As of 2022[update], this was the last time a Republican was elected to the U.S. Senate from Illinois during a presidential election year, the last time an Illinois Republican won a Senate election by double digits, and the last time any candidate has swept every county in the state.
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| Turnout | 51.24% | ||||||||||||||||
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County results | |||||||||||||||||
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The primary (held on March 21) and general election coincided with those for House and state elections.[1]
Turnout in the primaries was 31.40%, with a total of 1,753,727 votes cast.[1]
Turnout during the general election was 51.24%, with 3,184,764 votes cast.[1]
Turnout in both the primary and general election was significantly less than those for coinciding statewide races.[1]
Congressman Roman Pucinski defeated Dakin Williams in the Democratic primary. Williams was a prosecutor who was the younger brother of playwright Tennessee Williams.[2]
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | Roman C. Pucinski | 859,890 | 70.62 | |
| Democratic | W. Dakin Williams | 357,744 | 29.38 | |
| Democratic | Write Ins | 71 | 0 | |
| Total votes | 1,217,705 | 100 | ||
Incumbent Charles H. Percy was renominated without opposition in the Republican primary.
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Republican | Charles H. Percy (incumbent) | 535,911 | 99.98 | |
| Write-in | Others | 111 | 0.02 | |
| Total votes | 536,022 | 100 | ||
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Republican | Charles H. Percy (incumbent) | 2,867,078 | 62.21% | +7.27% | |
| Democratic | Roman Pucinski | 1,721,031 | 37.35% | -6.55% | |
| Socialist Labor | Edward C. Gross | 13,384 | 0.29% | ||
| Communist | Arnold Becchetti | 6,103 | 0.13% | ||
| Write-in | Others | 784 | 0.02% | ||
| Majority | 1,146,047 | 24.87% | +13.82% | ||
| Turnout | 3,822,724 | ||||
| Republican hold | Swing | ||||
