I’m currently reading Larry Bartels’ 1991 American Political Science Review article, “Constituency Opinion and Congressional Policy Making: The Reagan Defense Buildup” (gated, summary). I was struck by the following line in his literature review:
If Brady is right — if large-scale turnover in Congress is a necessary precondition for significant policy change — then the prospects for such change do appear bleak. It has become increasingly difficult to envision an electoral upheaval of sufficient magnitude to produce congressional turnover on the scale of the classic “critical elections” of earlier eras.
Obviously, just 3 years after Bartels published this observation, Republicans took control of both the House and the Senate by winning 54 seats and 8 seats, respectively. Oops.