List of United States Senate elections in Pennsylvania

United States Senate elections in Pennsylvania occur when voters in the U.S. Commonwealth of Pennsylvania select an individual to represent the state in the United States Senate in either of the state's two seats allotted by the U.S. Constitution. Regularly scheduled general elections occur on Election 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 the state legislature for staggered six-year terms. After the election of the founding members of the U.S. Senate in 1788, the Senate was divided into three 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 the 17th Amendment to the Constitution in 1913, U.S. senators are elected 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 major third-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).

List of recent elections

Parties^{[note 1]}

  Independent   Democratic   Republican   Prohibition   Progressive Party (1924)   Progressive Party (1912)

Class 1

County-level results of previous two Class 1 Senate elections

2018 election, between Bob Casey, Jr. (blue) and Lou Barletta (red)

2024 election, between Dave McCormick (red) and Bob Casey, Jr. (blue)

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.

Class 3

County-level results of previous two Class 3 Senate elections

2016 election, between Pat Toomey (red) and Katie McGinty (blue)

2022 election, between John Fetterman (blue) and Mehmet Oz (red)

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.

Notes

1. As listed on the ballot and in election returns.
2. In 1922, a special election and a regularly scheduled general election were held simultaneously for the Class 1 seat. David Reed had been appointed in August 1922 to fill the vacancy created by the death of William E. Crow (who had been appointed to fill a vacancy created by the death of Philander C. Knox) until the election of a successor. Reed was subsequently elected both to complete the term ending on March 4, 1923 (upper row), and to a full six-year term beginning on March 4, 1923 (lower row).
3. John Heinz died in a mid-air collision between two aircraft, one of which he was aboard, in April 1991. Democrat Harris Wofford was appointed by Governor Robert P. Casey in May 1991 to fill the vacancy. He was subsequently elected to serve the remainder of Heinz's term in the special election of November 1991.
4. In 1922, in addition to a special/general election for the Class 1 seat, a special election for the Class 3 seat was held. George W. Pepper was appointed by Governor William Sproul to fill the vacancy following the death of Boies Penrose in December 1921. Pepper was subsequently elected in 1922 to serve the remainder of Penrose's term.
5. Although William S. Vare won the 1926 election, his victory was controversial and overshadowed by scandal. As a result, Governor Gifford Pinchot refused to certify the results and Vare (having never been sworn-in) was formally unseated by the U.S. Senate in December 1929. Joseph R. Grundy was appointed later that month by Governor John S. Fisher to fill the vacancy until the next election.
6. Specter changed party registration from Republican to Democratic in April 2009. He subsequently lost the primary election to Sestak.

Graphs of results

Class 1 results from 1916 to 2024

10

20

30

40

50

60

70

80

90

100

1916

1922 (special)

1922

1928

1934

1940

1946

1952

1958

1964

1970

1976

1982

1988

1991 (special)

1994

2000

2006

2012

2018

2024

•   Republican
•   Major Third Party (>5%)
•   Other
•   Democratic

Class 3 results from 1914 to 2022

10

20

30

40

50

60

70

80

90

100

1914

1920

1922 (special)

1926

1930 (special)

1932

1938

1944

1950

1956

1962

1968

1974

1980

1986

1992

1998

2004

2010

2016

2022

•   Republican
•   Major Third Party (>5%)
•   Other
•   Democratic

See also

• List of United States senators from Pennsylvania
• List of Pennsylvania gubernatorial elections
• List of United States presidential elections in Pennsylvania
• Elections in Pennsylvania
• Government of Pennsylvania