Closest U.S. Senate elections in California

The tightest U.S. Senate races California has held, ranked by the margin between the top two candidates.

The closest U.S. Senate election in California history was in 1986, a margin of 1.4 points. Alan Cranston beat Ed Zschau, 3,646,672 to 3,541,804. Next closest are 1994 (1.9 points) and 1914 (2.8 points).

Every state is ranked together on Closest U.S. Senate elections in history. For every Senate race California has held, special elections included, see the California U.S. Senate hub.

What is the closest Senate race in California history?

The California Senate election decided by the narrowest margin was in 1986, 1.4 points. Alan Cranston beat Ed Zschau, 3,646,672 to 3,541,804. The next closest were 1994 (1.9 points) and 1914 (2.8 points).

How is the margin measured?

As the gap in vote share between the first and second-place finishers, from the certified general-election count. It is not adjusted for recounts, runoffs or later court rulings; the figure is the result as certified.

Does this include special elections?

No. These are the regular general elections for California’s two Senate seats. Special elections to fill a vacancy appear on the California Senate hub, which lists every race including specials, and in a few states one of those is closer than anything here.

Why does the list start in 1914?

Because senators were chosen by state legislatures before the Seventeenth Amendment. 1914 is the first cycle of the popular-vote era for the Senate, so it is the first California election with a popular margin to measure.

Closest U.S. Senate elections in California
#ElectionResultVotesMargin
11986Alan Cranston D def. Ed Zschau R3,646,672 – 3,541,8041.4 points
21994Dianne Feinstein D def. Michael Huffington R3,979,152 – 3,817,0251.9 points
31914James Duval Phelan D def. Francis J. Heney P279,896 – 255,2322.8 points
41964George Murphy R def. Pierre Salinger D3,628,552 – 3,411,9153.1 points
51976S. I. Hayakawa R def. John V Tunney D3,748,973 – 3,502,8623.3 points
61944Sheridan Downey D def. Frederick F. Houser R1,728,155 – 1,576,5534.6 points
71992Barbara Boxer D def. Bruce Herschensohn R5,173,467 – 4,644,1824.9 points
81968Alan Cranston D def. Max Rafferty R3,680,352 – 3,329,1485.0 points
91982Pete Wilson R def. Edmund G. Brown Jr. D4,022,565 – 3,494,9686.8 points
102018Dianne Feinstein D def. Kevin de Leon D6,019,422 – 5,093,9428.3 points
111920Samuel Morgan Shortridge R def. James Duval Phelan D447,835 – 371,5808.3 points
121956Thomas H. Kuchel R def. Richard Richards D2,892,918 – 2,445,8168.3 points
131988Pete Wilson R def. Leo McCarthy D5,143,409 – 4,287,2538.8 points
141970John V Tunney D def. George Murphy R3,496,558 – 2,877,6179.5 points
151938Sheridan Downey D def. Philip Bancroft R1,372,314 – 1,126,2409.8 points
161946William F. Knowland R def. Will Rogers Jr. D1,428,067 – 1,167,1619.9 points
172010Barbara Boxer D def. Carly Fiorina R5,218,441 – 4,217,36610.0 points
181998Barbara Boxer D def. Matt Fong R4,410,056 – 3,575,07810.1 points
191932William G. McAdoo D def. Tallant Tubbs R943,164 – 669,67612.6 points
201962Thomas H. Kuchel R def. Richard Richards D3,180,483 – 2,452,83912.9 points
211958Clair Engle D def. Goodwin J. Knight R2,927,693 – 2,204,33714.1 points
222024Adam B. Schiff D def. Steve Garvey R9,036,252 – 6,312,59417.7 points
231950Richard Nixon R def. Helen G. Douglas D2,183,454 – 1,502,50718.5 points
242000Dianne Feinstein D def. Tom Campbell R5,932,522 – 3,886,85319.3 points
251980Alan Cranston D def. Paul Gann R4,704,098 – 3,091,67119.4 points

How this ranking is measured

U.S. Senate general elections in California, ranked by the smallest gap in vote share between the top two finishers, 1914 to the present, closest 25 shown. Served from the senate_race_margin materialized view. Special elections are excluded, and so is any contest where the top two did not draw at least 1,000 votes between them or where the recorded winner was not the vote leader. The national list of the closest Senate races anywhere applies a 50,000-vote floor, which is why a small early race can appear here and not there.

Compiled by PolitiFinder · published June 14, 2026 · sources: Data & sources · data last verified September 25, 2026.