I doubt that very few young people today know the truth about the Democratic Party and is roots.
So…it appears that your thought is leading to young people should not support the Democratic Party because of what you believe they supported 100-150 years ago?
Using that logic, you could hate all Americans because, in the past, America supported slavery and did not give women the right to vote. You could hate all Germans because, in the past, Germans supported anti-semitism. And you could hate all Republicans because, in the past, Republicans supported Bush. (sorry, had to throw that one in)
I don’t care what the long ago dead members of the Republican or Democratic parties did or thought 100+ years ago…I care what they are doing right now .