This is a product of the climate of hate created by the progressive left and the Democrats.
They have questioned the legitimacy of President Trumps election from the moment it happened, plotting action against him (including but not limited to impeachment) from about 10 PM Eastern on November 8.
Left-wing educators have called for Trumps assassination, and it is only after this shooting that the hypocrites at the Huffington Post pulled an article urging the same.
They have promoted and defended Kathy Griffin and the severed Trump head. they have supported and defended the assassination of Trump at Shakespeare in the Park. Madonna said she had given serious thought to blowing up the White House. Snoop dogg pointed a gun at a Trump head, done up like a clown.
Is it any wonder one of their little mind-numbed robots decided that the Republicans needed killing?