We derive an optimal fiscal policy rule that reflects the US government’s desire to reduce fluctuations in the output gap and the primary deficit in the post-World War II period. The results from Bayesian estimations show a lower weight on output gap stabilization under predominant democratic presidencies relative to republican ones. The opposite holds with respect to maintaining a zero primary deficit. Our time-consistent fiscal rule indicates a countercyclical government response to GDP fluctuations at all times.