Cook Partisan Voting Index

The Cook Partisan Voting Index (CPVI), sometimes referred to as simply the Partisan Voting Index (PVI), is a measurement of how strongly an American congressional district leans toward one political party compared to the nation as a whole. It was developed in 1997 by Charlie Cook of the Cook Political Report, a nonpartisan political newsletter, working with Polidata, a political statistics analysis firm.

The index for each congressional district is derived by averaging its results from the prior two presidential elections and comparing them to national results. The index indicates which party's candidate was more successful in that district, as well as the number of percentage points by which its results exceeded the national average. The index is formatted as a letter + number; in a district whose CPVI score is R+2, recent Republicans presidential candidates received 2 percentage points more votes than the national average. Likewise, a CPVI score of D+3 shows the Democrats received 3 percentage points more votes than the national average..

Extremes

The most Democratic congressional districts in the country are New York's 15th and 16th at D+43, while the most Republican district is Utah's 1st with a PVI of R+26. As for states as a whole, Utah is the most Republican at R+22, and Massachusetts, New York and Rhode Island are the most Democratic at D+15 (and D+39 for the District of Columbia).

The most Republican congressional district to be represented by a Democrat is Texas's 17th congressional district, which has a CPVI of R+18. It is represented by Chet Edwards. The most Democratic congressional district to be represented by a Republican is Delaware's At-large congressional district, which has a CPVI of D+7. It is represented by Michael N. Castle.

There are currently 15 Democratic leaning districts represented by Republicans and 50 Republican leaning districts represented by a Democrat. Therefore 65 of the 434 districts which are currently represented, are represented by a member of the opposite party than the way which the district leans politically. This is a cross-over rate of about 15%. There are actually 435 districts, but Ohio's 11th district is vacant due to a recent death. It is extremely unlikely that this district would increase the number of districts voting for the opposite party as this district is extremely partisan at D+33.

List of PVIs

By congressional district

State	District	PVI	Party in Congress
Alabama	1st	087R+12	Republican
Alabama	2nd	086R+13	Republican
Alabama	3rd	095R+4	Republican
Alabama	4th	083R+16	Republican
Alabama	5th	093R+6	Democratic
Alabama	6th	074R+25	Republican
Alabama	7th	117D+17	Democratic
Alaska	At-large	085R+14	Republican
Arizona	1st	097R+2	Republican
Arizona	2nd	090R+9	Republican
Arizona	3rd	093R+6	Republican
Arizona	4th	114D+14	Democratic
Arizona	5th	095R+4	Democratic
Arizona	6th	087R+12	Republican
Arizona	7th	110D+10	Democratic
Arizona	8th	098R+1	Democratic
Arkansas	1st	101D+1	Democratic
Arkansas	2nd	099R+0	Democratic
Arkansas	3rd	088R+11	Republican
Arkansas	4th	100D+0	Democratic
California	1st	110D+10	Democratic
California	2nd	086R+13	Republican
California	3rd	092R+7	Republican
California	4th	088R+11	Republican
California	5th	114D+14	Democratic
California	6th	121D+21	Democratic
California	7th	119D+19	Democratic
California	8th	136D+36	Democratic
California	9th	138D+38	Democratic
California	10th	109D+9	Democratic
California	11th	096R+3	Democratic
California	12th	122D+22	Democratic
California	13th	122D+22	Democratic
California	14th	118D+18	Democratic
California	15th	114D+14	Democratic
California	16th	116D+16	Democratic
California	17th	117D+17	Democratic
California	18th	103D+3	Democratic
California	19th	089R+10	Republican
California	20th	105D+5	Democratic
California	21st	086R+13	Republican
California	22nd	083R+16	Republican
California	23rd	109D+9	Democratic
California	24th	094R+5	Republican
California	25th	092R+7	Republican
California	26th	095R+4	Republican
California	27th	113D+13	Democratic
California	28th	125D+25	Democratic
California	29th	112D+12	Democratic
California	30th	120D+20	Democratic
California	31st	130D+30	Democratic
California	32nd	117D+17	Democratic
California	33rd	136D+36	Democratic
California	34th	123D+23	Democratic
California	35th	133D+33	Democratic
California	36th	111D+11	Democratic
California	37th	127D+27	Democratic
California	38th	120D+20	Democratic
California	39th	113D+13	Democratic
California	40th	091R+8	Republican
California	41st	090R+9	Republican
California	42nd	089R+10	Republican
California	43rd	113D+13	Democratic
California	44th	093R+6	Republican
California	45th	096R+3	Republican
California	46th	093R+6	Republican
California	47th	105D+5	Democratic
California	48th	091R+8	Republican
California	49th	089R+10	Republican
California	50th	094R+5	Republican
California	51st	107D+7	Democratic
California	52nd	090R+9	Republican
California	53rd	112D+12	Democratic
Colorado	1st	118D+18	Democratic
Colorado	2nd	108D+8	Democratic
Colorado	3rd	093R+6	Democratic
Colorado	4th	090R+9	Republican
Colorado	5th	083R+16	Republican
Colorado	6th	089R+10	Republican
Colorado	7th	102D+2	Democratic
Connecticut	1st	114D+14	Democratic
Connecticut	2nd	108D+8	Democratic
Connecticut	3rd	112D+12	Democratic
Connecticut	4th	105D+5	Republican
Connecticut	5th	104D+4	Democratic
Delaware	At-large	107D+7	Republican
Florida	1st	080R+19	Republican
Florida	2nd	097R+2	Democratic
Florida	3rd	116D+16	Democratic
Florida	4th	083R+16	Republican
Florida	5th	094R+5	Republican
Florida	6th	091R+8	Republican
Florida	7th	096R+3	Republican
Florida	8th	096R+3	Republican
Florida	9th	095R+4	Republican
Florida	10th	101D+1	Republican
Florida	11th	111D+11	Democratic
Florida	12th	094R+5	Republican
Florida	13th	095R+4	Republican
Florida	14th	089R+10	Republican
Florida	15th	095R+4	Republican
Florida	16th	097R+2	Democratic
Florida	17th	135D+35	Democratic
Florida	18th	095R+4	Republican
Florida	19th	121D+21	Democratic
Florida	20th	118D+18	Democratic
Florida	21st	093R+6	Republican
Florida	22nd	104D+4	Democratic
Florida	23rd	129D+29	Democratic
Florida	24th	096R+3	Republican
Florida	25th	095R+4	Republican
Georgia	1st	085R+14	Republican
Georgia	2nd	102D+2	Democratic
Georgia	3rd	080R+19	Republican
Georgia	4th	122D+22	Democratic
Georgia	5th	125D+25	Democratic
Georgia	6th	080R+19	Republican
Georgia	7th	080R+19	Republican
Georgia	8th	091R+8	Democratic
Georgia	9th	075R+24	Republican
Georgia	10th	085R+14	Republican
Georgia	11th	081R+18	Republican
Georgia	12th	102D+2	Democratic
Georgia	13th	110D+10	Democratic
Hawaii	1st	107D+7	Democratic
Hawaii	2nd	110D+10	Democratic
Idaho	1st	080R+19	Republican
Idaho	2nd	076R+23	Republican
Illinois	1st	135D+35	Democratic
Illinois	2nd	135D+35	Democratic
Illinois	3rd	110D+10	Democratic
Illinois	4th	131D+31	Democratic
Illinois	5th	118D+18	Democratic
Illinois	6th	096R+3	Republican
Illinois	7th	135D+35	Democratic
Illinois	8th	094R+5	Democratic
Illinois	9th	120D+20	Democratic
Illinois	10th	104D+4	Republican
Illinois	11th	098R+1	Republican
Illinois	12th	105D+5	Democratic
Illinois	13th	094R+5	Republican
Illinois	14th	094R+5	Democratic
Illinois	15th	093R+6	Republican
Illinois	16th	095R+4	Republican
Illinois	17th	105D+5	Democratic
Illinois	18th	094R+5	Republican
Illinois	19th	091R+8	Republican
Indiana	1st	108D+8	Democratic
Indiana	2nd	095R+4	Democratic
Indiana	3rd	083R+16	Republican
Indiana	4th	082R+17	Republican
Indiana	5th	079R+20	Republican
Indiana	6th	088R+11	Republican
Indiana	7th	109D+9	Democratic
Indiana	8th	090R+9	Democratic
Indiana	9th	092R+7	Democratic
Iowa	1st	105D+5	Democratic
Iowa	2nd	107D+7	Democratic
Iowa	3rd	101D+1	Democratic
Iowa	4th	100D+0	Republican
Iowa	5th	091R+8	Republican
Kansas	1st	079R+20	Republican
Kansas	2nd	092R+7	Democratic
Kansas	3rd	095R+4	Democratic
Kansas	4th	087R+12	Republican
Kentucky	1st	089R+10	Republican
Kentucky	2nd	086R+13	Republican
Kentucky	3rd	102D+2	Democratic
Kentucky	4th	087R+12	Republican
Kentucky	5th	091R+8	Republican
Kentucky	6th	092R+7	Democratic
Louisiana	1st	081R+18	Republican
Louisiana	2nd	128D+28	Democratic
Louisiana	3rd	094R+5	Democratic
Louisiana	4th	092R+7	Republican
Louisiana	5th	089R+10	Republican
Louisiana	6th	092R+7	Democratic
Louisiana	7th	092R+7	Republican
Maine	1st	106D+6	Democratic
Maine	2nd	104D+4	Democratic
Maryland	1st	089R+10	Republican
Maryland	2nd	108D+8	Democratic
Maryland	3rd	107D+7	Democratic
Maryland	4th	130D+30	Democratic
Maryland	5th	109D+9	Democratic
Maryland	6th	086R+13	Republican
Maryland	7th	125D+25	Democratic
Maryland	8th	120D+20	Democratic
Massachusetts	1st	115D+15	Democratic
Massachusetts	2nd	111D+11	Democratic
Massachusetts	3rd	111D+11	Democratic
Massachusetts	4th	117D+17	Democratic
Massachusetts	5th	109D+9	Democratic
Massachusetts	6th	110D+10	Democratic
Massachusetts	7th	118D+18	Democratic
Massachusetts	8th	131D+31	Democratic
Massachusetts	9th	115D+15	Democratic
Massachusetts	10th	108D+8	Democratic
Michigan	1st	097R+2	Democratic
Michigan	2nd	090R+9	Republican
Michigan	3rd	090R+9	Republican
Michigan	4th	096R+3	Republican
Michigan	5th	112D+12	Democratic
Michigan	6th	097R+2	Republican
Michigan	7th	097R+2	Republican
Michigan	8th	097R+2	Republican
Michigan	9th	099R+0	Republican
Michigan	10th	095R+4	Republican
Michigan	11th	098R+1	Republican
Michigan	12th	113D+13	Democratic
Michigan	13th	132D+32	Democratic
Michigan	14th	133D+33	Democratic
Michigan	15th	113D+13	Democratic
Minnesota	1st	098R+1	Democratic
Minnesota	2nd	096R+3	Republican
Minnesota	3rd	098R+1	Republican
Minnesota	4th	113D+13	Democratic
Minnesota	5th	121D+21	Democratic
Minnesota	6th	094R+5	Republican
Minnesota	7th	093R+6	Democratic
Minnesota	8th	104D+4	Democratic
Mississippi	1st	089R+10	Democratic
Mississippi	2nd	110D+10	Democratic
Mississippi	3rd	086R+13	Republican
Mississippi	4th	083R+16	Democratic
Missouri	1st	126D+26	Democratic
Missouri	2nd	090R+9	Republican
Missouri	3rd	108D+8	Democratic
Missouri	4th	088R+11	Democratic
Missouri	5th	112D+12	Democratic
Missouri	6th	094R+5	Republican
Missouri	7th	085R+14	Republican
Missouri	8th	088R+11	Republican
Missouri	9th	092R+7	Republican
Montana	At-large	088R+11	Republican
Nebraska	1st	088R+11	Republican
Nebraska	2nd	090R+9	Republican
Nebraska	3rd	075R+24	Republican
Nevada	1st	109D+9	Democratic
Nevada	2nd	091R+8	Republican
Nevada	3rd	101D+1	Republican
New Hampshire	1st	099R+0	Democratic
New Hampshire	2nd	103D+3	Democratic
New Jersey	1st	114D+14	Democratic
New Jersey	2nd	104D+4	Republican
New Jersey	3rd	103D+3	Republican
New Jersey	4th	098R+1	Republican
New Jersey	5th	095R+4	Republican
New Jersey	6th	112D+12	Democratic
New Jersey	7th	098R+1	Republican
New Jersey	8th	112D+12	Democratic
New Jersey	9th	113D+13	Democratic
New Jersey	10th	134D+34	Democratic
New Jersey	11th	093R+6	Republican
New Jersey	12th	108D+8	Democratic
New Jersey	13th	123D+23	Democratic
New Mexico	1st	102D+2	Republican
New Mexico	2nd	093R+6	Republican
New Mexico	3rd	106D+6	Democratic
New York	1st	103D+3	Democratic
New York	2nd	107D+7	Democratic
New York	3rd	102D+2	Republican
New York	4th	109D+9	Democratic
New York	5th	118D+18	Democratic
New York	6th	138D+38	Democratic
New York	7th	128D+28	Democratic
New York	8th	128D+28	Democratic
New York	9th	114D+14	Democratic
New York	10th	141D+41	Democratic
New York	11th	140D+40	Democratic
New York	12th	134D+34	Democratic
New York	13th	101D+1	Republican
New York	14th	126D+26	Democratic
New York	15th	143D+43	Democratic
New York	16th	143D+43	Democratic
New York	17th	121D+21	Democratic
New York	18th	110D+10	Democratic
New York	19th	098R+1	Democratic
New York	20th	096R+3	Democratic
New York	21st	109D+9	Democratic
New York	22nd	106D+6	Democratic
New York	23rd	099R+0	Republican
New York	24th	098R+1	Democratic
New York	25th	103D+3	Republican
New York	26th	096R+3	Republican
New York	27th	107D+7	Democratic
New York	28th	115D+15	Democratic
New York	29th	094R+5	Republican
North Carolina	1st	109D+9	Democratic
North Carolina	2nd	096R+3	Democratic
North Carolina	3rd	084R+15	Republican
North Carolina	4th	106D+6	Democratic
North Carolina	5th	084R+15	Republican
North Carolina	6th	082R+17	Republican
North Carolina	7th	096R+3	Democratic
North Carolina	8th	096R+3	Republican
North Carolina	9th	087R+12	Republican
North Carolina	10th	084R+15	Republican
North Carolina	11th	092R+7	Democratic
North Carolina	12th	111D+11	Democratic
North Carolina	13th	102D+2	Democratic
North Dakota	At-large	086R+13	Democratic
Ohio	1st	098R+1	Republican
Ohio	2nd	086R+13	Republican
Ohio	3rd	096R+3	Republican
Ohio	4th	085R+14	Republican
Ohio	5th	089R+10	Republican
Ohio	6th	100D+0	Democratic
Ohio	7th	093R+6	Republican
Ohio	8th	087R+12	Republican
Ohio	9th	109D+9	Democratic
Ohio	10th	106D+6	Democratic
Ohio	11th	133D+33	Vacant
Ohio	12th	098R+1	Republican
Ohio	13th	106D+6	Democratic
Ohio	14th	097R+2	Republican
Ohio	15th	098R+1	Republican
Ohio	16th	095R+4	Republican
Ohio	17th	114D+14	Democratic
Ohio	18th	093R+6	Democratic
Oklahoma	1st	086R+13	Republican
Oklahoma	2nd	094R+5	Democratic
Oklahoma	3rd	081R+18	Republican
Oklahoma	4th	086R+13	Republican
Oklahoma	5th	087R+12	Republican
Oregon	1st	106D+6	Democratic
Oregon	2nd	088R+11	Republican
Oregon	3rd	118D+18	Democratic
Oregon	4th	100D+0	Democratic
Oregon	5th	101D+1	Democratic
Pennsylvania	1st	136D+36	Democratic
Pennsylvania	2nd	139D+39	Democratic
Pennsylvania	3rd	097R+2	Republican
Pennsylvania	4th	096R+3	Democratic
Pennsylvania	5th	089R+10	Republican
Pennsylvania	6th	102D+2	Republican
Pennsylvania	7th	104D+4	Democratic
Pennsylvania	8th	103D+3	Democratic
Pennsylvania	9th	084R+15	Republican
Pennsylvania	10th	091R+8	Democratic
Pennsylvania	11th	105D+5	Democratic
Pennsylvania	12th	105D+5	Democratic
Pennsylvania	13th	108D+8	Democratic
Pennsylvania	14th	122D+22	Democratic
Pennsylvania	15th	102D+2	Republican
Pennsylvania	16th	088R+11	Republican
Pennsylvania	17th	092R+7	Democratic
Pennsylvania	18th	097R+2	Republican
Pennsylvania	19th	087R+12	Republican
Rhode Island	1st	116D+16	Democratic
Rhode Island	2nd	113D+13	Democratic
South Carolina	1st	089R+10	Republican
South Carolina	2nd	090R+9	Republican
South Carolina	3rd	085R+14	Republican
South Carolina	4th	084R+15	Republican
South Carolina	5th	093R+6	Democratic
South Carolina	6th	111D+11	Democratic
South Dakota	At-large	089R+10	Democratic
Tennessee	1st	085R+14	Republican
Tennessee	2nd	088R+11	Republican
Tennessee	3rd	091R+8	Republican
Tennessee	4th	096R+3	Democratic
Tennessee	5th	106D+6	Democratic
Tennessee	6th	095R+4	Democratic
Tennessee	7th	087R+12	Republican
Tennessee	8th	100D+0	Democratic
Tennessee	9th	118D+18	Democratic
Texas	1st	082R+17	Republican
Texas	2nd	087R+12	Republican
Texas	3rd	082R+17	Republican
Texas	4th	082R+17	Republican
Texas	5th	083R+16	Republican
Texas	6th	084R+15	Republican
Texas	7th	083R+16	Republican
Texas	8th	079R+20	Republican
Texas	9th	121D+21	Democratic
Texas	10th	086R+13	Republican
Texas	11th	074R+25	Republican
Texas	12th	085R+14	Republican
Texas	13th	081R+18	Republican
Texas	14th	085R+14	Republican
Texas	15th	103D+3	Democratic
Texas	16th	109D+9	Democratic
Texas	17th	081R+18	Democratic
Texas	18th	123D+23	Democratic
Texas	19th	074R+25	Republican
Texas	20th	108D+8	Democratic
Texas	21st	086R+13	Republican
Texas	22nd	084R+15	Democratic
Texas	23rd	095R+4	Democratic
Texas	24th	084R+15	Republican
Texas	25th	101D+1	Democratic
Texas	26th	087R+12	Republican
Texas	27th	098R+1	Democratic
Texas	28th	098R+1	Democratic
Texas	29th	108D+8	Democratic
Texas	30th	126D+26	Democratic
Texas	31st	084R+15	Republican
Texas	32nd	088R+11	Republican
Utah	1st	073R+26	Republican
Utah	2nd	082R+17	Democratic
Utah	3rd	077R+22	Republican
Vermont	At-large	108D+8	Democratic
Virginia	1st	090R+9	Republican
Virginia	2nd	093R+6	Republican
Virginia	3rd	118D+18	Democratic
Virginia	4th	094R+5	Republican
Virginia	5th	093R+6	Republican
Virginia	6th	088R+11	Republican
Virginia	7th	088R+11	Republican
Virginia	8th	114D+14	Democratic
Virginia	9th	092R+7	Democratic
Virginia	10th	094R+5	Republican
Virginia	11th	098R+1	Republican
Washington	1st	107D+7	Democratic
Washington	2nd	103D+3	Democratic
Washington	3rd	100D+0	Democratic
Washington	4th	086R+13	Republican
Washington	5th	092R+7	Republican
Washington	6th	106D+6	Democratic
Washington	7th	130D+30	Democratic
Washington	8th	102D+2	Republican
Washington	9th	106D+6	Democratic
West Virginia	1st	093R+6	Democratic
West Virginia	2nd	094R+5	Republican
West Virginia	3rd	100D+0	Democratic
Wisconsin	1st	097R+2	Republican
Wisconsin	2nd	113D+13	Democratic
Wisconsin	3rd	103D+3	Democratic
Wisconsin	4th	120D+20	Democratic
Wisconsin	5th	087R+12	Republican
Wisconsin	6th	094R+5	Republican
Wisconsin	7th	102D+2	Democratic
Wisconsin	8th	100D+0	Democratic
Wyoming	At-large	080R+19	Republican

By state

State	PVI
Alabama	091R+8
Alaska	085R+14
Arizona	098R+1
Arkansas	096R+3
California	106D+6
Colorado	098R+1
Connecticut	109D+9
Delaware	107D+7
District of Columbia	139D+39
Florida	101D+1
Georgia	093R+6
Hawaii	109D+9
Idaho	080R+19
Illinois	109D+9
Indiana	092R+7
Iowa	101D+1
Kansas	088R+11
Kentucky	091R+8
Louisiana	095R+4
Maine	105D+5
Maryland	110D+10
Massachusetts	115D+15
Michigan	104D+4
Minnesota	103D+3
Mississippi	092R+7
Missouri	098R+1
Montana	088R+11
Nebraska	084R+15
Nevada	101D+1
New Hampshire	102D+2
New Jersey	109D+9
New Mexico	101D+1
New York	115D+15
North Carolina	094R+5
North Dakota	086R+13
Ohio	099R+0
Oklahoma	087R+12
Oregon	103D+3
Pennsylvania	103D+3
Rhode Island	115D+15
South Carolina	092R+7
South Dakota	089R+10
Tennessee	096R+3
Texas	091R+8
Utah	077R+22
Vermont	108D+8
Virginia	096R+3
Washington	104D+4
West Virginia	095R+4
Wisconsin	102D+2
Wyoming	080R+19

References

• Cook Political Report, PVI for the 110th Congress. Cook Political Report. Retrieved on 2008-10-08..