>>Trump just didn't respond properly to the NY correspondent during his press-conference.

I think the first step is to determine who is making the threats. Some in the MSM of course attribute it to Trump-voting rednecks responding to Trump's anti-Semitic rhetoric. But if we ignore that sort of fake news: who is doing it and why? Are these dry runs, or the actions of a few idiots who get their jollies by causing a ruckus, or evidence of growing anti-Semitism, bearing in mind that most hate crime in the US already is directed against Jews?

Whatever their motivation- I'm not sure what Trump can do to prevent people phoning in bomb scares. I suppose the calling number can be traced, but only a dullard will leave a trail of crumbs to themselves.

Sorry but until there's some clarity on who is doing this and why, you need to keep treating threats as serious. But also, watch the watchers: there's a good chance whoever is responsible is in the audience to enjoy the chaos they caused, or more ominously, to look for weaknesses in the way you respond.