Trump has routinely shown he cares only about himself
A principle of behavioral psychology is that the best predictor of future behavior is past behavior. We have 60-plus years of history for the two major party candidates that may give us an indication of the future should they be elected.
Hillary Clinton, even with her flaws, has demonstrated over six decades that she works hard to make the world a better place for others.
Donald Trump, also with his flaws, has demonstrated over six decades that he works hard to make the world a better place for Donald Trump.
There we have the essence of our two major party candidates.