Understanding the Legality Behind Trump's Executive Order on Immigration

The last couple of weeks have been a whirlwind of news regarding Mr. Trump's recent executive order on immigration.  When the order was first announced, the emotional response of so many Americans (myself included) was overwhelming. People with US visas and greencards from all over the world were refused boarding on US-bound flights, or turned around upon arrival, or detained in US airports.  Protests erupted in airports all over the country.  Personal accounts of people directly affected began circulating.  It was dizzying, and for so many people (again, myself included) frightening and confusing.  Then US District Senior Judge James Robart of Seattle issued a nationwide restraining order to temporarily block the ban.  Again, an onslaught of emotion and information erupted.  The White House issued statements, various political figures spoke up, the press published it all.  And then, the three-judge panel on the Ninth Circuit Court of Appeals upheld the stay on the executive order.  And now...it looks like this will go to the Supreme Court to decide if Trump's executive order is lawful.  

In this storm of legal events and reactionary events and press coverage, I found myself looking for information and clarification.  I wanted answers to questions of legality.  What powers, exactly, does the president have in issuing executive orders?  Are their limits to those powers?  What power does the Judiciary branch have in this matter?  How does this process work, and what's the timeframe on it?

I recently found this article by Charlie Savage for the New York Times which greatly helped me understand the recent events, the ruling of the Appeals Court, and the legal issues involved.  The article prints sections of the Court of Appeals' ruling, and follows each with commentary that relates it to the events that I have seen and heard in the media coverage. It does a fantastic job at showing exactly what legal questions are involved, and what the next steps in the process will be.  I especially appreciate reading the excerpts from the ruling, and seeing exactly what areas of the US law they relate to.