Donald Trump appears likely to be the Republican candidate for president. This does not mean that he will become president, but it does mean that he might. It also means that the basic dynamic of the American political system has shifted, suggesting the behavior of the United States might change. And that makes Trump a matter of geopolitical interest.
These geopolitical consequences cannot be considered until we have looked at how and why Trump differs from other candidates and why he has emerged as a political power.