United States Senate elections in Pennsylvania occur when voters in theU.S. Commonwealth ofPennsylvania select an individual to represent the state in theUnited States Senate in either of the state's two seats allotted by theU.S. Constitution. Regularly scheduledgeneral elections occur onElection Day, coinciding with various other federal, statewide, and local races.
Per the original text of the U.S. Constitution, each state was allotted two U.S. senators selected by thestate legislature for staggered six-year terms. After the election of thefounding members of the U.S. Senate in1788, the Senate was divided intothree groups, or "classes" (Class 1, Class 2, and Class 3) to stagger the six-year terms of its members. Per Article I, Section 3, Clause 2 of the Constitution, the founding members of Class 1 would serve two years, Class 2 four years, and Class 3 six years. All senators elected thereafter would serve full six-year terms such that one-third of the Senate would be up for re-election every two years.[1] Pennsylvania was assigned a Class 1 seat and a Class 3 seat.[2][3] Since the passage of the17th Amendment to the Constitution in 1913, U.S. senators areelected directly to six-year terms by the voters of each state at the general election held on Election Day.Special elections may be held to fill mid-term vacancies by electing an individual to serve the remainder of the unexpired term.[4] The next Class 1 U.S. Senate election in Pennsylvania is scheduled for November 5, 2030, and the next Class 3 election in Pennsylvania is scheduled for November 7, 2028.
The list below contains election returns from all twenty Class 1 and twenty-one Class 3 post-17th Amendment U.S. Senate elections in Pennsylvania, including special elections, sorted by year and beginning with the first in 1914 and the most recent in 2024. Incumbent senators are listed as well as elected senators and runner(s)-up in each election, including majorthird-party candidates (garnering 5% or more of the popular vote). Parties are color-coded to the left of a Senator's or candidate's name according to the key below. The popular vote and percentage margins listed in the "Margin" column are the differences between the total votes received and percentage of the popular vote received by the top two finishers in the corresponding election (i.e. the margin-of-victory of an elected Senator over the nearest competitor).
Independent Democratic Republican Prohibition Progressive Party (1924) Progressive Party (1912)
| Election* | Incumbent Senator | Elected Senator | Votes | Runner(s)-up | Votes | Margin | Notes | |||
|---|---|---|---|---|---|---|---|---|---|---|
| 1916 | George T. Oliver | Philander C. Knox | 680,451 (56.36%) | Ellis L. Orvis | 450,106 (37.28%) | 230,345 (19.08%) | [5] | |||
| 1922* | David A. Reed | David A. Reed | 860,483 (86.15%) | Others | 138,377 (13.85%) | — | [6] [note 2] | |||
| David A. Reed | David A. Reed | 802,146 (56.04%) | Samuel E. Shull | 423,583 (29.59%) | 378,563 (26.45%) | |||||
| William J. Burke | 127,180 (8.88%) | |||||||||
| 1928 | David A. Reed | David A. Reed | 1,948,646 (64.38%) | William N. McNair | 1,029,055 (34.00%) | 919,591 (30.38%) | [7] | |||
| 1934 | David A. Reed | Joseph F. Guffey | 1,494,001 (50.78%) | David A. Reed | 1,366,877 (46.46%) | 127,124 (4.32%) | [8] | |||
| 1940 | Joseph F. Guffey | Joseph F. Guffey | 2,069,980 (51.79%) | Jay Cooke | 1,893,104 (47.36%) | 176,876 (4.43%) | [9] | |||
| 1946 | Joseph F. Guffey | Edward Martin | 1,853,458 (59.26%) | Joseph F. Guffey | 1,245,338 (39.81%) | 608,120 (19.45%) | [10] | |||
| 1952 | Edward Martin | Edward Martin | 2,331,034 (51.57%) | Guy K. Bard | 2,168,546 (47.98%) | 162,488 (3.59%) | [11] | |||
| 1958 | Edward Martin | Hugh Scott | 2,042,586 (51.21%) | George M. Leader | 1,929,821 (48.38%) | 112,765 (2.83%) | [12] | |||
| 1964 | Hugh Scott | Hugh Scott | 2,429,858 (50.64%) | Genevieve Blatt | 2,353,223 (49.05%) | 76,635 (1.59%) | [13] | |||
| 1970 | Hugh Scott | Hugh Scott | 1,874,106 (51.43%) | William Sesler | 1,653,774 (45.38%) | 220,332 (6.05%) | [14] | |||
| 1976 | Hugh Scott | John Heinz | 2,381,891 (52.39%) | William Green | 2,126,977 (46.78%) | 254,914 (5.61%) | [15] | |||
| 1982 | John Heinz | John Heinz | 2,136,418 (59.28%) | Cyril Wecht | 1,412,965 (39.20%) | 723,453 (20.08%) | [16] | |||
| 1988 | John Heinz | John Heinz | 2,901,715 (66.45%) | Joe Vignola | 1,416,764 (32.45%) | 1,484,951 (34.00%) | [17] | |||
| 1991* | Harris Wofford | Harris Wofford | 1,860,760 (55.01%) | Dick Thornburgh | 1,521,986 (44.99%) | 338,774 (10.02%) | [18] [note 3] | |||
| 1994 | Harris Wofford | Rick Santorum | 1,735,691 (49.40%) | Harris Wofford | 1,648,481 (46.92%) | 87,210 (2.48%) | [19] | |||
| 2000 | Rick Santorum | Rick Santorum | 2,481,962 (52.42%) | Ron Klink | 2,154,908 (45.51%) | 327,054 (6.91%) | [20] | |||
| 2006 | Rick Santorum | Bob Casey, Jr. | 2,392,984 (58.68%) | Rick Santorum | 1,684,778 (41.32%) | 708,206 (17.36%) | [21] | |||
| 2012 | Bob Casey, Jr. | Bob Casey, Jr. | 3,021,364 (53.69%) | Tom Smith | 2,509,132 (44.59%) | 512,232 (9.10%) | [22] | |||
| 2018 | Bob Casey, Jr. | Bob Casey, Jr. | 2,792,437 (55.74%) | Lou Barletta | 2,134,848 (42.62%) | 657,589 (13.12%) | [23] | |||
| 2024 | Bob Casey, Jr. | Dave McCormick | 3,399,295 (48.82%) | Bob Casey, Jr. | 3,384,180 (48.60%) | 15,115 (0.22%) | [24] | |||
Note: Asterisk (*) next to year denotes a special election.
| Election* | Incumbent Senator | Elected Senator | Votes | Runner(s)-up | Votes | Margin | Notes | |||
|---|---|---|---|---|---|---|---|---|---|---|
| 1914 | Boies Penrose | Boies Penrose | 519,801 (46.75%) | Gifford Pinchot | 269,235 (24.22%) | 250,566 (22.53%) | [25] | |||
| A. Mitchell Palmer | 266,415 (23.96%) | |||||||||
| 1920 | Boies Penrose | Boies Penrose | 1,069,785 (59.98%) | John A. Farrell | 484,352 (24.22%) | 585,433 (35.76%) | [26] | |||
| Leah C. Marion | 132,610 (7.44%) | |||||||||
| 1922* | George W. Pepper | George W. Pepper | 819,507 (57.60%) | Fred Kerr | 468,330 (32.92%) | 351,177 (24.68%) | [27] [note 4] | |||
| 1926 | George W. Pepper | William S. Vare | 822,178 (54.64%) | William B. Wilson | 648,680 (43.11%) | 173,498 (11.53%) | [28] | |||
| 1930* | Joseph R. Grundy | James J. Davis | 1,462,186 (71.54%) | Sedgwick Kistler | 523,338 (25.61%) | 938,848 (45.93%) | [29] [note 5] | |||
| 1932 | James J. Davis | James J. Davis | 1,368,707 (49.35%) | Lawrence H. Rupp | 1,200,322 (43.28%) | 168,385 (6.07%) | [30] | |||
| 1938 | James J. Davis | James J. Davis | 2,086,932 (54.72%) | George H. Earle | 1,694,464 (43.11%) | 392,468 (11.61%) | [31] | |||
| 1944 | James J. Davis | Francis J. Myers | 1,864,735 (49.99%) | James J. Davis | 1,840,943 (49.35%) | 23,792 (0.64%) | [32] | |||
| 1950 | Francis J. Myers | James H. Duff | 1,820,400 (51.30%) | Francis J. Myers | 1,694,076 (47.74%) | 126,324 (3.56%) | [33] | |||
| 1956 | James H. Duff | Joseph S. Clark, Jr. | 2,268,641 (50.08%) | James H. Duff | 2,250,671 (49.69%) | 17,970 (0.39%) | [34] | |||
| 1962 | Joseph S. Clark, Jr. | Joseph S. Clark, Jr. | 2,238,383 (51.06%) | James E. Van Zandt | 2,134,649 (48.70%) | 103,734 (2.36%) | [35] | |||
| 1968 | Joseph S. Clark, Jr. | Richard Schweiker | 2,399,762 (51.90%) | Joseph S. Clark, Jr. | 2,117,662 (45.80%) | 282,100 (6.10%) | [36] | |||
| 1974 | Richard Schweiker | Richard Schweiker | 1,843,317 (53.00%) | Peter F. Flaherty | 1,596,121 (45.89%) | 247,196 (7.11%) | [37] | |||
| 1980 | Richard Schweiker | Arlen Specter | 2,230,404 (50.48%) | Peter F. Flaherty | 2,122,391 (48.04%) | 108,013 (2.44%) | [38] | |||
| 1986 | Arlen Specter | Arlen Specter | 1,906,537 (56.44%) | Robert W. Edgar | 1,448,219 (42.87%) | 458,318 (13.57%) | [39] | |||
| 1992 | Arlen Specter | Arlen Specter | 2,358,125 (49.10%) | Lynn Yeakel | 2,224,966 (46.33%) | 133,159 (2.77%) | [40] | |||
| 1998 | Arlen Specter | Arlen Specter | 1,814,180 (61.34%) | William R. Lloyd, Jr. | 1,028,839 (34.79%) | 785,341 (26.55%) | [41] | |||
| 2004 | Arlen Specter | Arlen Specter | 2,925,080 (52.62%) | Joe Hoeffel | 2,334,126 (41.99%) | 590,954 (10.63%) | [42] | |||
| 2010 | Arlen Specter | Pat Toomey | 2,028,945 (51.01%) | Joe Sestak | 1,948,716 (48.99%) | 80,229 (2.02%) | [43] [note 6] | |||
| 2016 | Pat Toomey | Pat Toomey | 2,951,702 (48.77%) | Kathleen McGinty | 2,865,012 (47.34%) | 86,690 (1.43%) | [44] | |||
| 2022 | Pat Toomey | John Fetterman | 2,751,012 (51.03%) | Mehmet Oz | 2,487,260 (46.03%) | 208,334 (4.04%) | [45] | |||
Note: Asterisk (*) next to year denotes a special election.
| Class 1 |  | |
|---|---|---|
| Class 3 | ||
| Notes | † Never officially seated | |
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