Congressional symmetry: years remaining mirror years served in the U.S. House and Senate

Genus

Journal of Population Sciences

Table 1 Three sets sub-tables containing numbers of party transitions for the 100 members of the 1980 U.S. Senate during the growth (first elected) and senescence (senate departure) phases

C. Cycle-level transition sequence
TO	TO	FROM
TO	TO	D¹	R¹
D²	D³	12 (DDD)	17 (RDD)	29	59
D²	R³	16 (DDR)	14 (RDR)	30	59
		28	31	59
R²	D³	9 (DRD)	4 (RRD)	13	41
R²	R³	20 (DRR)	8 (RRR)	28	41
		29	12	41
					100

D and R denote Democrat and Republican, respectively, and the transition direction follows from their order in the 2 × 2 tables with the superscript indicating the sequence order. For example in sub-Tables A and B, D¹D² denotes “from Democrat to Democrat” and R¹D² denotes “from Republican to Democrat”. Thus in the growth phase of the 1980 Senate 27 Democrats replaced their Democrat predecessor (DD) and 31 Republicans were replaced by Democrats (RD). Sub-Table C contains the transitions across the entire life cycle. The superscripts again indicate the order. R¹D²D³ indicates the successor’s, incumbent’s and successor’s parties were R, D and D, respectively. Thus 17 seats were flipped by the D incumbents who, in turn, were replaced by another D