The title of this column is "Teaching Civility In The Time Of Trump" which infers that it is he that is causing the rift.  And yet, all these hate groups existed before he came to office. 
The big division started with Hillary's divide and conquer campaign.
She spoke of white against black, rich against poor, man against woman, straight against gay. Now the media has continued to carry the same flag and stir it up in an attempt to blame Trump and so the Republican Party, and all that voted for President Trump.  Sad.