| Alabama | Richard C. ShelbyR | 1,242,200 votes · +647,182 over Wayne Sowell |
| Alaska | Lisa MurkowskiR | 149,773 votes · +9,349 over Tony Knowles |
| Arizona | John McCainR | 1,505,372 votes · +1,100,865 over Stuart Starky |
| Arkansas | Blanche Lambert LincolnD | 580,973 votes · +122,937 over Jim Holt |
| California | Barbara BoxerD | 6,955,728 votes · +2,399,806 over Bill Jones |
| Colorado | Ken SalazarD | 1,081,188 votes · +100,520 over Pete Coors |
| Connecticut | Christopher J. DoddD | 945,347 votes · +487,598 over Jack C. Orchulli |
| Florida | Mel MartinezR | 3,672,864 votes · +82,663 over Betty Castor |
| Georgia | Johnny IsaksonR | 1,864,202 votes · +576,512 over Denise L. Majette |
| Hawaii | Daniel K. InouyeD | 313,629 votes · +226,457 over Cam Cavasso |
| Idaho | Mike CrapoR | 499,796 votes |
| Illinois | Barack ObamaD | 3,597,456 votes · +2,206,766 over Alan L. Keyes |
| Indiana | Evan BayhD | 1,496,976 votes · +593,063 over Marvin Scott |
| Iowa | Charles E. GrassleyR | 1,038,175 votes · +625,810 over Arthur Small |
| Kansas | Sam BrownbackR | 780,863 votes · +470,526 over Lee Jones |
| Kentucky | Jim BunningR | 873,507 votes · +22,652 over Daniel Mongiardo |
| Louisiana | David VitterR | 943,014 votes · +400,864 over Christopher John |
| Maryland | Barbara A. MikulskiD | 1,504,691 votes · +721,636 over E. J. Pipkin |
| Missouri | Christopher S. BondR | 1,518,089 votes · +359,828 over Nancy Farmer |
| Nevada | Harry ReidD | 494,805 votes · +210,165 over Richard Ziser |
| New Hampshire | Judd GreggR | 434,847 votes · +213,298 over Doris R. Haddock |
| New York | Charles E. SchumerI | 4,769,824 votes · +3,144,755 over Howard Mills |
| North Carolina | Richard BurrR | 1,791,450 votes · +158,923 over Erskine B. Bowles |
| North Dakota | Byron L. DorganD | 212,143 votes · +113,590 over Mike Liffrig |
| Ohio | George VoinovichR | 3,464,356 votes · +1,503,185 over Eric D. Fingerhut |
| Oklahoma | Thomas A. CoburnR | 763,433 votes · +166,683 over Brad Carson |
| Oregon | Ron WydenD | 1,128,728 votes · +563,474 over Al King |
| Pennsylvania | Arlen SpecterR | 2,925,080 votes · +590,954 over Joseph M. Hoeffel |
| South Carolina | Jim DemintR | 857,167 votes · +152,783 over Inez Tenenbaum |
| South Dakota | John R. ThuneR | 197,848 votes · +4,508 over Thomas A. Daschle |
| Utah | Robert F. BennettR | 626,640 votes · +367,685 over R. Paul van Dam |
| Vermont | Patrick J. LeahyD | 216,972 votes · +141,574 over Jack McMullen |
| Washington | Patty MurrayD | 1,549,708 votes · +345,124 over George R. Nethercutt |
| Wisconsin | Russel D. FeingoldD | 1,632,697 votes · +331,514 over Tim Michels |