Which presidents win more or less than expected in Congress? A Biden update

This article updates estimates of which presidents won more or fewer votes than should be expected through President Biden's first two years in office. Multiple regression models estimating the effects of contextual variables (party, public approval, and party polarization plus interactions) establish a common baseline. Errors reveal which presidents won more or less than should be expected. Party polarization conditions relationships between party control and presidential success, but effects differ across chambers. As polarization increases in the House, majority presidents win more votes and minority presidents win fewer. The effects are less obvious in the Senate. Majority presidents win more than do minority presidents regardless of polarization. But polarization has led to a de facto 60-vote Senate, as the minority party uses the supermajority required to invoke cloture to block confirmation of presidential appointments. Conclusions discuss limitations of roll-call vote measures of presidential success.