I recommend reading Rosa Brooks’s analysis of Donald Trump’s foreign policy at Foreign Policy. Here’s the meat of her analysis:
Trump’s vision of the world — and his conception of statecraft — isn’t one I much like, but it reflects a fairly coherent theory of international relations. It’s realist, transactional, and Machiavellian — and it demands a serious, thoughtful, and nondefensive response.
I can’t imagine circumstances under which I’d vote for Trump but Ms. Brooks offers a very solid explanation of why dismissing him, practically a parlor game among pundits and politicians, is ill-considered:
Every time someone in the Media Elite pokes fun at Donald Trump, it inspires six bad-tempered middle Americans to vote for him. And every time someone in the Media Elite utters a pompous condemnation of Trump’s ignorance and folly, 17 more angry Trump voters are created. If Trump becomes president, guys, it’s gonna be your fault.