Since 1860, a Republican has occupied the White House for 95 years, a Democrat 65. The annualized S&P 500 return during the 65 Democratic years of control was 8.4%, 8.3% when the President was a Republican, a statistically insignificant difference. From 1929-2019 one party controlled both ends of Pennsylvania Avenue for 45 years and the S&P 500 return averaged 7.45% during those years; the other 46 years, it was 7.26%/year.