This is the perfect storm of "idiot shooting his mouth off" and "media rising to autistic levels of literalistic stupidity." Trump wasn't calling for Civil War 2, and most of the people excoriating him realize that.
I'm still not sure how "He's an idiot who says dangerous things" is a selling point for Trump, when those same people are blaming Obama's extremely mild rhetoric for attacks on police.
Obama: "The police acted stupidly." APS: "OMG IT'S HIS FAULT ANYTIME A COP GETS A PAPERCUT!"
Trump: "I love dictators, especially Putin! I don't think we should support NATO unless they pay us ransom. And I might just nuke some people for the hell of it." APS: "It's so refreshing to have someone who speaks his mind!"