2012 United States presidential election in California

The 2012 United States presidential election in California took place on November 6, 2012, as part of the 2012 United States presidential election in which all 50 states plus the District of Columbia participated. California voters chose 55 electors, the most out of any state, to represent them in the Electoral College via a popular vote pitting incumbent Democratic President Barack Obama and his running mate, Vice President Joe Biden, against Republican challenger and former Massachusetts Governor Mitt Romney and his running mate, Congressman Paul Ryan.

Prior to the election, every major news network considered California to be a state Obama would win or as a safe blue state. According to Secretary of State Debra Bowen's website, the President won the popular vote with 60.24% percent, with Mitt Romney in second place at 37.12%, and Libertarian candidate Gary Johnson in third place at 1.10%. The Democrats have won the state in every presidential election after Republican George H. W. Bush won the state in 1988.

As of the 2020 presidential election, this is the last presidential election in which the nominee from the Republican Party won Orange County—a longtime, traditional bastion for the national GOP—and Nevada County. With its 55 electoral votes, California was Obama's largest electoral prize in 2012.

Democratic primary
The 2012 California Democratic presidential primary took place on June 5, 2012, as part of the 2012 Democratic Party presidential primaries.

! Candidate ! Popular vote ! % ! Delegates ! Total ! 2,076,309 ! 100% ! 609
 * style="text-align:left;" | Barack Obama (incumbent)
 * 2,075,905
 * 100%
 * 547.0
 * style="text-align:left;" | Darcy Richardson (write-in)
 * 221
 * 0.00%
 * 0.0
 * style="text-align:left;" | Michael W.R. Meyer, Jr. (write-in)
 * 129
 * 0.00%
 * 0.0
 * style="text-align:left;" | Louis Alberto Ramos, Jr. (write-in)
 * 54
 * 0.00%
 * 0.0
 * style="text-align:left;"| Uncommitted
 * colspan="2" N/A
 * 62.0
 * 0.0
 * style="text-align:left;"| Uncommitted
 * colspan="2" N/A
 * 62.0
 * 62.0
 * }

Republican primary
The 2012 California Republican Party presidential primary took place on June 5, 2012, as part of the 2012 Republican Party presidential primaries. 169 delegates were chosen, for a total of 172 delegates at the 2012 Republican National Convention.

As noted in the Green Papers for California, "159 district delegates are to be bound to presidential contenders based on the primary results in each of the 53 congressional districts: each congressional district is assigned 3 National Convention delegates and the presidential contender receiving the greatest number of votes in that district will receive all 3 of that district's National Convention delegates. 10 at-large delegates (10 base at-large delegates plus 0 bonus delegate) are to be bound to the presidential contender receiving the greatest number of votes in the primary statewide.  In addition, 3 party leaders, the National Committeeman, the National Committeewoman, and the chairman of the California's Republican Party, will attend the convention as unpledged delegates by virtue of their position."

! Candidate ! Popular vote ! % ! Delegates ! Total ! 1,924,970 ! 100% ! 172
 * style="text-align:left;" | Mitt Romney
 * 1,530,513
 * 79.51%
 * 169
 * style="text-align:left;" | Ron Paul
 * 199,246
 * 10.35%
 * 0
 * style="text-align:left;" | Rick Santorum (withdrawn)
 * 102,258
 * 5.31%
 * 0
 * style="text-align:left;" | Newt Gingrich (withdrawn)
 * 72,022
 * 3.74%
 * 0
 * style="text-align:left;" | Charles E. "Buddy" Roemer, III (withdrawn)
 * 12,520
 * 0.65%
 * 0
 * style="text-align:left;" | Fred Karger
 * 8,393
 * 0.44%
 * 0
 * style="text-align:left;" | Jeremy Hannon (write-in)
 * 11
 * 0.00%
 * 0
 * style="text-align:left;" | Donald James Gonzales (write-in)
 * 5
 * 0.00%
 * 0
 * style="text-align:left;" | Sheldon Yeu Howard (write-in)
 * 2
 * 0.00%
 * 0
 * style="text-align:left;"| Uncommitted
 * colspan="2" N/A
 * 3
 * 0
 * style="text-align:left;" | Sheldon Yeu Howard (write-in)
 * 2
 * 0.00%
 * 0
 * style="text-align:left;"| Uncommitted
 * colspan="2" N/A
 * 3
 * colspan="2" N/A
 * 3
 * }

Green primary
The 2012 California Green Party presidential primary took place on June 5, 2012, as part of the 2012 Green Party presidential primaries.

Libertarian primary
The 2012 California Libertarian Party presidential primary took place on June 5, 2012, as part of the 2012 Libertarian Party presidential primaries.

The primary was non-binding, and took place after Gary Johnson had already won the Libertarian nomination at the Party's 2012 convention.

American Independent
The American Independent Party, a far-right and paleoconservative political party that formed when endorsing the candidacy of George Wallace in 1968 held a small presidential primary on June 5. It was won by Edward C. Noonan. However, the party would instead opt to nominate Tom Hoefling for president.

General election
Candidate Ballot Access: Write-In Candidate Access:
 * Mitt Romney/Paul Ryan, Republican
 * Barack Obama/Joseph Biden, Democratic
 * Gary Johnson/James P. Gray, Libertarian
 * Jill Stein/Cheri Honkala, Green
 * Tom Hoefling/Robert Ornelas, Independent
 * Roseanne Barr/Cindy Sheehan, Peace and Freedom
 * Virgil Goode/Jim Clymer, Constitution
 * Rocky Anderson/Luis J. Rodriguez, Justice
 * James Harris/Maura DeLuca, Socialist Workers
 * Stewart Alexander/Alejandro Mendoza, Socialist
 * Jerry White/Phyllis Scherrer, Socialist Equality
 * Stephen Durham/Christina Lopez, Freedom Socialist
 * Ron Paul/Andrew Napolitano

Counties that flipped from Democratic to Republican

 * Butte (largest city: Chico)
 * Nevada (largest town: Truckee)
 * Trinity (largest community: Weaverville)

Outcome by city
Official outcomes by city.

By congressional district
Obama won 41 of the 53 congressional districts, including 3 held by Republicans.