Party Cohesion
on Party Votes*
|
Year
|
Democrat
|
Republican
|
|
1961
|
71%
|
72%
|
|
1962
|
69%
|
68%
|
|
1963
|
71%
|
72%
|
|
1964
|
67%
|
69%
|
|
1965
|
69%
|
70%
|
|
1966
|
61%
|
67%
|
|
1967
|
66%
|
71%
|
|
1968
|
57%
|
63%
|
|
1969
|
62%
|
62%
|
|
1970
|
57%
|
59%
|
|
1971
|
62%
|
66%
|
|
1972
|
57%
|
64%
|
|
1973
|
68%
|
68%
|
|
1974
|
63%
|
62%
|
|
1975
|
69%
|
70%
|
|
1976
|
65%
|
66%
|
|
1977
|
67%
|
70%
|
|
1978
|
64%
|
67%
|
|
1979
|
69%
|
72%
|
|
1980
|
68%
|
70%
|
|
1981
|
69%
|
76%
|
|
1982
|
72%
|
71%
|
|
1983
|
76%
|
74%
|
|
1984
|
74%
|
72%
|
|
1985
|
79%
|
75%
|
|
1986
|
78%
|
71%
|
|
1987
|
81%
|
74%
|
|
1988
|
79%
|
73%
|
|
1989
|
81%
|
73%
|
|
1990
|
81%
|
74%
|
|
1991
|
81%
|
78%
|
|
1992
|
79%
|
79%
|
|
1993
|
85%
|
84%
|
|
1994
|
83%
|
83%
|
|
1995
|
80%
|
91%
|