TL;DR - I've been genuinely in awe at, perplexed by and deeply worried for you guys for a long time now. But it's not really just America that's at fault here. The world in general is pretty messed up and the US simply happens to be a shiny example that's easy to look at.
Long reply:
I'm from Europe.
I'm kind of curious why anyone outside of Trump's immediate follower base bothers to take him seriously at all. The Trump crowd are either idiots or simply enjoy trolling.
I personally called Trump v Sanders for 2016 a while ago and if that were the case, Trump would lose. He might have the support of a large part of the Republican base, but in the grand scheme of things that's really not decisive or even important at all. Far more worrisome is the fact that this circus has started two years before the actual election. This among many other things is why to me American politics is little more than a neverending sitcom (that gets people killed). That's also the one reason American politics is pretty much the only bit of regular news I follow - mostly though "liberal" channels: Last Week Tonight, Comedy Central's political satire shows and Real Time.
The sad part is that it's not the news I'm after - it's this (in particular the question starting at 1:00):
On a more serious note - to me things got real when Obama won the reelection v Romney by a very narrow margin. That scared me. You guys only just had a crazy out of touch with reality douche in the White House. I mean, W was genuinely stupid. But he had no energy, so despite all the mess he created, the damage could've been far worse. Trump would probably start building the wall on day one.
The reason he's not really harmful, though, is because he is playing directly into the Democratic agenda - he's effectively taking out any viable candidates the GOP might have and with Clinton doing a wonderful job blowing up her own campaign, you'll end up with the one idiot who can't win versus the only person who should win. Which is a good thing.
Last time it was Herman Cain for GOP who somewhat filled the void that Trump is currently filling, but I think he eventually admitted to not having any intention of actually getting anywhere with his campaign and was, for all intents and purposes, doing little more than trolling the system. I think he even had an interview where he slipped and sounded intelligent and much better informed than his fellow candidates. The sad part is unlike Cain, Trump is not trolling and really is that crazy.
The only reason I care is because despite your horrible political system and an exemplary propaganda machine that should, at best, belong in a book, Amuric'n influence is freaking far-reaching. So whatever the outcome, it will affect most people in the world, including me.
Incidentally, the world has no shortage of idiots who either are in or are running for office. Australia, Russia and England are all major powers and none are immune. Neither is my own country, although when an idiot is elected into office here, on a global scale it couldn't even theoretically hurt anyone.