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County results Kohl: 50–60% 60–70% 70–80% Engeleiter: 40–50% 50–60% 60–70% | |||||||||||||||||
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The1988 United States Senate election in Wisconsin took place on November 8, 1988. Incumbent Democratic U.S. SenatorWilliam Proxmire decided to retire, instead of running for re-election to a sixth full term. DemocratHerb Kohl won the open seat.

| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | Herb Kohl | 249,226 | 46.76% | |
| Democratic | Tony Earl | 203,479 | 38.18% | |
| Democratic | Ed Garvey | 55,225 | 10.36% | |
| Democratic | Doug La Follette | 19,819 | 3.72% | |
| Democratic | Edmond C. Hou-Seye | 5,040 | 0.95% | |
| Democratic | Write ins | 215 | 0.04% | |
| Total votes | 533,004 | 100% | ||
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Republican | Susan Engeleiter | 209,025 | 57.45% | |
| Republican | Steve King | 148,601 | 40.84% | |
| Republican | Peter Y. Taylor | 6,149 | 1.69% | |
| Republican | Write ins | 87 | 0.02% | |
| Total votes | 363,862 | 100% | ||
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | Herb Kohl | 1,128,625 | 52.08% | |
| Republican | Susan Engeleiter | 1,030,440 | 47.55% | |
| Independent | George W. Zaehringer | 3,965 | 0.18% | |
| Socialist Workers | Patricia Grogan | 3,029 | 0.14% | |
| Independent | Arlyn F. Wollenburg | 1,198 | 0.06% | |
| Democratichold | ||||
| Total votes | 2,167,257 | 100.00% | ||