Take a look at this article... so what exactly do we call these late 2018 folks who find problems with this 1968 Charlie Brown cartoon -- might I suggest THEY are the racists? Some of the article associated comments are also interesting reading.
...and a century before the 1968 cartoon was published, as Black Americans emerged from slavery, most regular Democrats both South and North were called exactly what? It takes time, even generations, to make historic demographic attitude changes. Today's Liberal leftists (aka: "progressives") need to get better educated and learn some tolerance. A character named Forrest Gump once remarked -- "stupid is as stupid does" -- seems appropriately applied to most 2018 liberals.
Note: The image inserted at the top of this post was found by simple Google Internet search, and displayed here for educational and non-profit use in accordance with copyright fair use doctrine.