The very reason Donald Trump is the nominee (presumptively) of the GOP is the reason a man shot up a gay nightclub in Florida.
Fear of the other.
The shooter, according to his father, was upset because he saw two men kissing each other. Is that any different from being upset that Obama is a black man in the White House (which is the root of birtherism, something Trump championed until he gave it up as a lost cause)? Is that any different than Kim Davis refusing to issue marriage license in accordance with the law? Is that any different than demanding a wall be built along the Mexican border to keep brown people from entering our country (because white Canadians don't "take our jobs," and besides, they speak English)? Is that any different from declaring a ban on "Muslims" (the majority of whom are Asian, the rest of whom live in Africa, but it's the minority of Muslim Arabs who are the face of Islam, apparently)?
Is there really any separation of the mindset of Donald Trump from the mindset that says I should shoot up gays in a nightclub because two men kissing upsets me? It is a distinction of intensity, since neither Trump nor his supporters (no word on the shooter's political inclinations, but who cares?) have taken to violence themselves. But the frustration that fuels Trump's campaign is of a piece with the anger that causes a man to murder as many people as he can.
Donald Trump wants to get elected on that fear. Indeed, the shooter is described as "belligerent, toxic, and racist." Precisely the attitude Trump represents.
Denise McAllister on NPR this morning, in support of Donald Trump and in response to the Orlando shootings, argued that Americans need to unite behind fear; that fear is needed to draw us together so we can fight the other, the enemy. We need, she said, to declare war so we can give police the free rein they need to investigate killers like this shooter. Cokie Roberts was too useless in opposition to point out this shooter had already been investigated twice by the FBI. Apparently we are to suspend the Constitution because this crisis is more serious than any war this country has ever faced, including the Civil War.
That is the fear Donald Trump wants to be elected on. That is the fear that drove a man to mass homicide. Fear is never something we need to encourage. FDR famously said we only needed to be afraid of fear; Donald Trump wants us to be afraid of everyone, so he can protect us from them. Which I'm truly afraid he cannot possibly do.