President                    Change pp
    Eisenhower                   -1.8
    Nixon                        +0.8
    Ford                         +0.8
    Carter                        0
    Reagan                       +0.5
    GHW Bush                     +1.8
    Clinton                      -6.1
    GW Bush                      +4.3
    Obama                        -6.6
    Trump                        +11
    Biden                        -5.8

But Trump 2 will definitely lower it, more than anyone has ever seen before.