The inherent disadvantage of the presidential party in midterm congressional elections

The almost inevitable midterm election loss suffered by the President's congressional party is by now an accepted fact among political scientists and politicians. Several explanations are current. The classic model is that of Campbell (1960) who posits that the weakness of short-term forces in a midterm election causes low-involvement voters from the previous on-year contest to abstain. Kernell (1977) attributes off-year outcomes to asymmetries of behavior on the part of voters, while Tufte (1978) focuses on economic cycles induced by the government.