The Cook Partisan Voting Index, abbreviated Cook PVI, CPVI, or PVI, is a measurement of how strongly a

United States congressional district Congressional districts in the United States are electoral divisions for the purpose of electing members of the United States House of Representatives. The number of voting seats in the House of Representatives is currently set at 435, with ...

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

leans toward the Democratic or Republican Party, compared to the nation as a whole, based on how that district or state voted in the previous two presidential elections. The index is updated after each presidential election cycle, as well as after congressional

redistricting Redistribution (re-districting in the United States and in the Philippines) is the process by which electoral districts are added, removed, or otherwise changed. Redistribution is a form of boundary delimitation that changes electoral dist ...

. ''

The Cook Political Report ''The Cook Political Report with Amy Walter'' is an American online newsletter that analyzes elections and campaigns for the U.S. Presidency, the United States Senate, the United States House of Representatives, and U.S. governors' offices. Sel ...

'' first introduced the PVI in August 1997 to better gauge the competitiveness of each district using the

1992 File:1992 Events Collage V1.png, From left, clockwise: 1992 Los Angeles riots, Riots break out across Los Angeles, California after the Police brutality, police beating of Rodney King; El Al Flight 1862 crashes into a residential apartment buildi ...

and

1996 File:1996 Events Collage.png, From left, clockwise: A Centennial Olympic Park bombing, bomb explodes at Centennial Olympic Park in Atlanta, set off by a radical Anti-abortion violence, anti-abortionist; The center fuel tank explodes on TWA Flight 8 ...

presidential elections as a baseline. The most recent iteration is the 2022 Cook Partisan Voting Index, which was released with an updated formula for calculating PVI values.

Calculation and format

The Cook PVI is displayed as a letter, a plus sign, and a number. The letter (either a D for Democratic or an R for

Republican Republican can refer to: Political ideology * An advocate of a republic, a type of government that is not a monarchy or dictatorship, and is usually associated with the rule of law. ** Republicanism, the ideology in support of republics or agains ...

) reflects the major party toward which the district (or state) leans. The number reflects the strength of that partisan preference in rounded percentage points. A district or state that "performed within half a point of the national average in either direction" is designated as "Even". PVIs are calculated by comparing the lead candidate's average share of the two-party presidential vote in the past two presidential elections to the party's national average two-party share for those elections. In 2022, it was updated to weigh the most recent presidential election more heavily than the prior election.

By congressional district

The PVIs for congressional districts are calculated based on the

2016 File:2016 Events Collage.png, From top left, clockwise: Bombed-out buildings in Ankara following the 2016 Turkish coup d'état attempt; the impeachment trial of Brazilian President Dilma Rousseff; Damaged houses during the 2016 Nagorno-Karabakh ...

and

2020 2020 was heavily defined by the COVID-19 pandemic, which led to global Social impact of the COVID-19 pandemic, social and Economic impact of the COVID-19 pandemic, economic disruption, mass cancellations and postponements of events, COVID- ...

presidential elections. With a PVI of R+1, was determined to be the median congressional district, meaning that exactly 217 districts are more Democratic and 217 are more Republican than this district. , in the House, there are 222 districts more Republican than the national average, and 206 districts more Democratic than the national average. The number of swing seats, defined as those between D+5 and R+5, is 82.

By state

The PVIs for states are calculated based on the results of the U.S. presidential elections in

and

. The table below reflects the current state of Congress and governors, based on the most recent election results.

Extremes and trends

The most Democratic district in the nation is , based in

Oakland Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the Bay A ...

, with a PVI value of D+40. The most

district in the nation is (R+33), represented by Republican

Robert Aderholt Robert Brown Aderholt (; born July 22, 1965) is an American politician and attorney serving as the U.S. representative for since 1997. He is a member of the Republican Party. The district includes most of Tuscaloosa County north of the Black W ...

. With a Cook PVI value of R+25,

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

is the most Republican state in the nation. At D+16,

Vermont Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to ...

is the most Democratic state, though

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

, is substantially more partisan with a PVI value of D+43. In the

Senate A senate is a deliberative assembly, often the upper house or chamber of a bicameral legislature. The name comes from the ancient Roman Senate (Latin: ''Senatus''), so-called as an assembly of the senior (Latin: ''senex'' meaning "the el ...

, the most Republican-leaning state to have a Democratic senator is

West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...

(R+22 PVI), represented by

Joe Manchin Joseph Manchin III (born August 24, 1947) is an American politician and businessman serving as the senior United States senator from West Virginia, a seat he has held since 2010. A member of the Democratic Party, Manchin was the 34th governor of ...

. The least Democratic-leaning state to have two Democratic senators is

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

(R+3 PVI), represented by

Jon Ossoff Thomas Jonathan Ossoff ( ; born February 16, 1987) is an American politician serving as the senior United States senator from Georgia since 2021. A member of the Democratic Party, Ossoff was previously a documentary filmmaker and investigativ ...

and

Raphael Warnock Raphael Gamaliel Warnock ( ; born July 23, 1969) is an American Baptist pastor and politician serving as the junior United States senator from Georgia since 2021. A member of the Democratic Party, he assumed office on January 20, 2021. Since 2 ...

. The most Democratic-leaning state to have a Republican senator is

Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...

(D+2 PVI), represented by

Susan Collins Susan Margaret Collins (born December 7, 1952) is an American politician serving as the senior United States senator from Maine. A member of the Republican Party, she has held her seat since 1997 and is Maine's longest-serving member of Co ...

. The least Republican-leaning states to have two Republican senators are

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

(R+3 PVI), represented by

Marco Rubio Marco Antonio Rubio (born May 28, 1971) is an American politician and lawyer serving as the senior United States senator from Florida, a seat he has held since 2011. A member of the Republican Party, he served as Speaker of the Florida Hous ...

and

Rick Scott Richard Lynn Scott ( Myers, born December 1, 1952) is an American politician serving as the junior United States senator from Florida since 2019. A member of the Republican Party, he was the 45th governor of Florida from 2011 to 2019. Scott ...

, and

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

(R+3 PVI), represented by

Richard Burr Richard Mauze Burr (born November 30, 1955) is an American businessman and politician who is the senior United States senator from North Carolina, serving since 2005. A member of the Republican Party, Burr was previously a member of the United ...

and

Thom Tillis Thomas Roland Tillis (born August 30, 1960) is an American politician serving as the junior United States senator from North Carolina since 2015. A Republican, he was elected to the North Carolina House of Representatives in 2006, and began servi ...

References

External links

The Cook Political Report
{{United States Congress Psephology United States congressional districts The Cook Political Report with Amy Walter

Calculation and format

By congressional district

By state

Extremes and trends

See also

References

External links