The let’s-circle-the-wagons effect lies at the heart of all identity politics, so raising it in the context of the Trump phenomenon isn’t really any more enlightening than pointing out the fruitless mutual name-calling that characterises such politics. There are local analogues aplenty.
I think what makes Trump unusual is not so much what he says as that he seems to have so much support. As an American friend of mine says, America has lost its collective mind.
What’s interesting is that the poles seem to be heftier than the middle. What’s entirely uninteresting is that that rather vast middle (i.e., “middle” in US terms) is aligned mostly along its own historical allegiances: most Republicans will vote red and most Democrats will vote blue. What would be as jaw-droppingly encouraging as it is unlikely to happen would be a US electorate that woke up to the realities it is facing and voted Independent.
Yup, but several things work against that. For one thing, America's system apparently pretty much ensures a two party system. Of course, it doesn't absolutely have to be the current two (which are essentially the same party anyway.) But people are so scared of Trump they tell me this election is too important to be the one in which they vote third party. They told me the same thing last election, and the one before it, and...
Every election, the same thing happens: on both sides, they see the other party's candidate as so scary that this election they just have to vote against him/her as an emergency measure; next election we'll all vote third party. This despite the fact that the U.S. president doesn't actually have all that much power, and America is a big dude and can survive two terms of Trump.
Another factor is that Hillary has successfully duped the traditional Democrat supporters into thinking she's the left wing candidate. In fact, just yesterday I had an American bloke tell me that I am wrong - Hillary is not right wing, she's the Democratic candidate and therefore she is by definition left wing. So yes, as you point out, they vote according to tradition and hardly even look at what their candidates are actually saying and doing and planning. Fact is, the current Democratic party has pretty much taken over the GOP's policies, while the latter has gone batshit crazy. Traditional right wingish voters should actually now support Hillary, and the leftish ones should vote for Stein.
But it won't happen this election because lots of votes for Stein will effectively ensure a Trump victory. Of course, it will also ensure that the Greens will have access to funding for the next election, and within a decade, the entire face of American politics will have shifted towards a more rational view. But voters don't think that far into the future; every election they vote tactically rather than on principle, because every election they go into panic mode about the opposing candidate.
Well, they richly deserve their leaders. They are one more reason why I have become determined that I'll sit out an election before I ever, ever again vote tactically rather than on principle. America neatly illustrates where tactical voting eventually leads. If the electorate has no principles, they can't really complain when their politicians don't have any either.
Apart from that, the fact that the US’s sphere of influence on most of the rest of the world is vastly disproportionate to its actual presence and that the choice of its leader currently is between a psychopath and a village bully, should be deeply concerning to any thinking observer. It’s the whole world that’s headed for “interesting times”, not just the US.
I fear you may be right - whichever of the two wins, we are headed for more war. Of course, this ultimately weakens them and their empire is slowly crumbling, and while one cannot help a bit of schadenfreude over that, the fact is that with America out of the way, it will be the Chinese who throw their weight around all over the world. We may live to long for the good old days when a few drone strikes in the Middle East were the worst of our worries about the world policeman...