All Pew Research Center surveys about U.S. politics and policy include questions about partisan affiliation. In 2014 a total of 25,010 respondents were asked the following:

In politics TODAY, do you consider yourself a Republican, Democrat, or independent?
(IF INDEPENDENT, OTHER, DON’T KNOW): As of today do you lean more to the Republican Party or more to the Democratic Party?

Detailed demographic breakdowns of party identification are presented here, or can be downloaded (CSV or PDF).
Report: A Deep Dive Into Party Affiliation

TotalWhite, Non-HispanicBlack, Non-HispanicHispanicAsian, Non-Hispanic

Total Population

Rep % Dem % Ind % (VOL.)
Other/DK %		 Rep/Lean
Rep %		 Dem/Lean
Dem %		 No
leaning %		 Unweighted N
TOTAL
23 32 39 6 39 48 13 25,010
GENDER
Men 24 26 45 5 43 44 13 12,843
Women 23 37 35 6 36 52 12 12,167
RACE/ETHNICITY
White, non-Hispanic 30 25 40 5 49 40 11 17,823
Black, non-Hispanic 5 64 26 5 11 80 9 2,496
Hispanic 13 34 44 9 26 56 18 2,594
Asian, non-Hispanic (English-speaking only) 11 37 46 6 23 65 12 641
GENERATION
Millennial (ages 18-33 in 2014) 18 28 48 6 35 51 14 5,315
Generation X (34-49) 22 32 40 6 38 49 13 5,206
Baby-Boomer (50-68) 25 34 35 5 41 47 11 9,392
Silent (69-86) 33 33 29 5 47 43 10 4,350
DETAILED GENERATION
Younger Millennial (18-25) 18 27 50 5 36 51 13 2,693
Older Millennial (26-33) 18 28 47 7 33 50 16 2,622
Younger Gen Xer (34-41) 20 31 43 6 36 49 14 2,326
Older Gen Xer (42-49) 23 33 37 7 40 48 12 2,880
Younger Boomer (50-58) 26 32 36 6 41 46 12 4,414
Older Boomer (59-68) 25 37 34 4 41 49 10 4,978
Younger Silent (69-78) 32 33 30 6 47 43 10 3,105
Older Silent (79-86) 35 34 27 4 48 43 9 1,245
EDUCATION
College graduate+ 24 34 39 4 40 52 9 10,270
Post graduate degree 20 38 38 4 35 57 8 3,972
College graduate 26 31 39 4 42 49 9 6,298
Some college or less 23 31 40 6 39 47 14 14,605
Some college 25 30 40 5 42 47 12 6,920
High school or less 22 31 40 7 37 47 16 7,685
FAMILY INCOME
$75,000+ 30 29 38 3 48 45 8 7,578
$30,000-$74,999 24 32 40 4 41 48 10 7,811
<$30,000 17 35 42 7 31 54 15 6,995
DETAILED FAMILY INCOME
$150,000+ 29 29 38 4 47 45 9 2,229
$100,000 to $149,999 30 30 37 3 48 45 6 2,566
$75,000 to $99,999 30 29 38 3 48 44 9 2,783
$50,000 to $74,999 27 30 38 4 45 45 9 3,483
$40,000 to $49,999 24 33 40 4 40 50 10 2,045
$30,000 to $39,999 19 33 43 4 37 51 13 2,283
<$30,000 17 35 42 7 31 54 15 6,995
EMPLOYED
Yes 23 30 40 7 39 48 14 2,056
Full-time 24 30 41 6 39 47 14 1,525
Part-time 22 31 39 9 37 49 14 531
No 22 35 34 9 36 49 15 1,238
MARITAL STATUS
Married 28 27 39 6 48 41 12 6,758
Unmarried 17 34 43 6 32 54 14 6,168
DETAILED MARITAL STATUS
Married 28 27 39 6 48 41 12 6,758
Living with a partner 13 32 50 6 31 55 14 779
Divorced/Separated 17 37 39 7 32 54 14 1,740
Widowed 27 38 30 5 40 49 11 1,231
Never married 15 33 47 5 30 56 14 2,418
PARENT OR GUARDIAN
Yes 21 30 42 7 38 47 15 1,207
No 23 31 40 6 39 48 13 3,618
GENERATION BY GENDER
Millennial men 18 23 53 5 38 48 14 3,088
Millennial women 18 33 43 6 32 54 14 2,227
Gen Xer men 23 26 45 6 43 44 13 2,823
Gen Xer women 21 38 35 7 33 53 13 2,383
Boomer men 26 29 39 5 45 43 12 4,735
Boomer women 24 39 31 5 38 52 11 4,657
Silent men 35 26 35 4 54 37 9 1,913
Silent women 31 39 25 6 42 48 10 2,437
EDUCATION 2-WAY BY GENDER
College grad men 25 26 45 4 45 46 9 5,485
College grad women 22 41 33 4 35 57 8 4,785
Some coll or less men 23 26 45 6 42 44 14 7,277
Some coll or less women 23 35 35 7 36 50 14 7,328
EDUCATION 4-WAY BY GENDER
Post graduate men 22 29 45 4 42 50 8 2,142
Post graduate women 18 46 32 4 29 64 7 1,830
College men 27 24 45 4 47 43 10 3,343
College women 25 37 33 5 38 53 8 2,955
Some college men 26 25 45 5 46 43 12 3,281
Some college women 24 35 36 5 38 51 12 3,639
HS or less men 22 27 44 6 40 44 16 3,996
HS or less women 22 35 35 8 34 49 16 3,689
MARITAL STATUS BY GENDER
Married men 28 23 43 6 51 38 11 3,715
Married women 28 31 35 6 44 44 12 3,043
Unmarried men 17 28 50 5 34 51 14 2,859
Unmarried women 17 39 38 6 29 57 14 3,309
PARENT BY GENDER
Parent men 24 27 44 6 43 42 15 606
Parent women 19 33 40 9 33 51 16 601
Non-parent men 24 26 45 5 42 46 13 1,834
Non-parent women 22 36 35 6 36 51 13 1,784
REGION
Northeast 20 36 38 6 34 53 13 4,334
New England (CT ME MA NH RI VT) 16 32 48 4 35 52 14 1,181
Middle Atlantic (DE DC MD NJ NY PA) 20 39 34 6 33 55 12 3,757
Midwest 24 31 40 6 40 47 13 5,657
Great Lakes-East North (IN IL MI OH WI) 23 32 39 6 39 48 12 3,794
Midwest-West North (IA KS MN MO NE ND SD) 26 28 40 6 43 43 14 1,863
South 25 30 39 5 42 46 12 9,268
South Atlantic (FL GA NC SC VA WV) 25 30 40 5 42 46 12 4,534
South Central (AL AR KY LA MS OK TN TX) 27 28 39 6 44 43 13 4,130
West 22 30 42 7 38 49 13 5,751
Mountain (AZ CO ID NM MT UT NV WY) 27 24 43 6 45 43 13 2,080
Pacific (AK CA HI OR WA) 19 33 41 7 34 53 14 3,671
COMMUNITY TYPE
Urban 18 38 39 6 31 57 12 8,118
Suburban 25 29 40 5 43 45 12 12,065
Rural 29 26 39 6 47 39 14 4,556
RELIGIOUS TRADITION
White Non-Hisp Evangelical Protestant 46 14 34 5 68 22 9 4,814
White Non-Hisp Mainline Protestant 30 26 38 6 48 40 12 4,144
Black Protestant 5 68 22 4 10 82 8 1,812
Total Catholic 24 33 37 6 40 48 12 5,125
White Non-Hispanic Catholic 31 30 36 3 50 41 10 3,435
Hispanic Catholic 12 38 41 9 25 58 17 1,283
Mormon 49 12 35 3 70 22 9 473
Jewish 16 47 33 4 31 61 8 516
Total Unaffiliated 10 34 50 6 25 61 14 4,983
Atheist 6 42 47 5 16 72 12 781
Agnostic 8 39 49 4 23 69 8 902
Nothing in particular 12 31 52 6 27 57 16 3,300
RELIGIOUS TRADITION BY GENERATION
White NH Evangelical Protestant Millennial 44 9 44 4 70 19 12 559
White NH Evangelical Protestant Xer 46 12 36 5 70 20 10 858
White NH Evangelical Protestant Boomer 45 16 34 5 68 23 9 1,984
White NH Evangelical Protestant Silent 51 18 26 5 67 25 8 1,255
White NH Mainline Protestant Millennial 29 22 44 6 48 37 15 576
White NH Mainline Protestant Xer 28 27 38 7 48 39 12 721
White NH Mainline Protestant Boomer 29 27 38 5 47 41 12 1,725
White NH Mainline Protestant Silent 33 30 32 5 49 41 10 964
Total Catholic Millennial 20 28 45 7 36 48 16 930
Total Catholic Xer 22 32 39 7 39 49 12 1,120
Total Catholic Boomer 26 37 33 4 41 48 11 2,005
Total Catholic Silent 27 38 30 4 44 46 10 919
White NH Catholic Millennial 32 24 42 2 49 39 12 387
White NH Catholic Xer 33 27 35 4 53 38 8 642
White NH Catholic Boomer 30 32 35 3 47 43 9 1,508
White NH Catholic Silent 30 33 34 4 49 41 10 769
Hispanic Catholic Millennial 12 30 48 10 28 53 20 449
Hispanic Catholic Xer 10 38 43 9 23 61 16 390
Hispanic Catholic Boomer 15 46 32 8 25 59 16 344
Total Unaffiliated Millennial 9 30 56 6 24 62 14 1,724
Total Unaffiliated Xer 11 35 49 5 26 60 14 1,171
Total Unaffiliated Boomer 12 36 46 6 25 60 14 1,556
Total Unaffiliated Silent 14 45 36 5 25 64 11 452