In the fifteen days since President Joe Biden pulled out of his re-election campaign and endorsed Vice President Kamala Harris, voters have increasingly grown even more concerned over Donald Trump’s age, health, mental fitness, and variety of other factors, while embracing newly-presumptive Democratic presidential nominee Kamala Harris on those same issues. A majority (51%) now see Donald Trump as too old to be president, and more than a third of voters doubt he would be able to serve a full four-year term. Morning Consult, in a new poll released Monday, offers additional good news for Vice Pr…