This index records the length of time since an incumbent has been defeated.  It ranks each individual state according to the duration of time in which there has been a 100% incumbent re-election rate (all incumbents seeking re-election in general elections were successful).  States in which an incumbent was recently defeated receive higher rankings in this index.

Ranking	State	# Elections of Incumbent Win Streak	# Races of Incumbent Win Streak
1	Illinois	0	0
1	Georgia	0	0
1	Indiana	0	0
1	Texas	0	0
5	Connecticut	1 (2 yrs)	5
5	Florida	1 (2 yrs)	23
5	Maryland	1 (2 yrs)	8
5	Minnesota	1 (2 yrs)	8
5	Nevada	1 (2 yrs)	3
5	New York	1 (2 yrs)	27
5	Ohio	1 (2 yrs)	18
5	Pennsylvania	1 (2 yrs)	16
13	Arkansas	2 (4 yrs)	8
13	California	2 (4 yrs)	101
15	Kansas	3 (6 yrs)	12
15	New Jersey	3 (6 yrs)	37
15	New Mexico	3 (6 yrs)	8
15	Washington	3 (6 yrs)	24
15	Wisconsin	3 (6 yrs)	24
20	Maine	4 (8 yrs)	7
20	Massachusetts	4 (8 yrs)	39
20	Michigan	4 (8 yrs)	58
20	North Carolina	4 (8 yrs)	45
20	Oregon	4 (8 yrs)	18
20	Utah	4 (8 yrs)	10
26	Virginia	5 (10 yrs)	51
26	New Hamshire	5 (10 yrs)	8
26	Nebraska	5 (10 yrs)	12
26	Kentucky	5 (10 yrs)	26
26	Iowa	5 (10 yrs)	23
26	Idaho	5 (10 yrs)	9
26	Arizona	5 (10 yrs)	30
33	Louisiana	6 (12 yrs)	36
33	Missouri	6 (12 yrs)	45
33	Montana	6 (12 yrs)	4
33	South Carolina	6 (12 yrs)	30
33	Alabama	6 (12 yrs)	39
38	Vermont	7 (14 yrs)	7
39	Rhode Island	8 (16 yrs)	12
39	Hawaii	8 (16 yrs)	15
41	Colorado	9 (18 yrs)	47
41	Mississippi	9 ( 18 yrs)	38
43	West Virginia	11 (22 yrs)	36
43	Delaware	11 (22 yrs)	10
45	South Dakota	12 (24 yrs)	9
46	Tennessee	15 (30 yrs)	117
46	Oklahoma	15 (30 yrs)	75
48	North Dakota	19 (38 yrs)	16
48	Alaska	19 (38 yrs)	17
50	Wyoming	20 (40 yrs)	14

Note: Incumbent win streaks are broken only by incumbent defeats in general elections; primary defeats are not reflected in this ranking system.