Until we know who this person is, and why they did what they did (Mental? Hate everyone that looks different which is far from normal behavior! Drug addictions? PTSD? Bipolar? Dementia? Brain injury? Meltdown of massive proportions? ) we will not know The Driver behind it. 

The WH has 100% nothing to do with this though.  Hate groups, online people, they might tip a teetering person right over the edge. 
 But not the WH.