The Effect of Incumbency on State Legislative Elections

Complete election returns are now available for the 1968-1986 period for 14 state legislatures that used single-member districts exclusively in both houses during that period. An analysis of incumbents shows that in most states there was only a modest increase over that period in the proportion who sought reelection or succeeded in getting reelected; the reason is that in most states that percentage was already high in 1968. There was, however, a significant increase in most states in the margin by which incumbents won, though not an increase in winning margins for open seats. In many states this increase was largely accounted for by an increase in the proportion of uncontested elections.