What did Donald Trump do today?

He justified giving Christian refugees a higher priority than Muslims by claiming that it had been "almost impossible" for Christians to be granted refugee status in the past.

This is completely false. 2016 was the first year in which Muslim refugees admitted to the US (38,901) narrowly outnumbered Christians (37,521). In every other year since 2006, more Christians were given refugee status than any other religious group, despite the refugee population as a whole being from predominantly Muslim regions. 

There is no way to know why (or if) Trump believes otherwise.

Trump today barred all entry to the United States for 90 days from seven predominantly Muslim countries in the Middle East, and suspended admission of all refugees into the United States for 120 days.  In part because of its absurdly complicated nature, no religious, ethnic, or political group within Syria has escaped harm during the six years of its civil war. 11 million people have fled their homes during the fighting. 

Why should anyone care about this?

• It's bad if major policy decisions affecting national security aren't based on facts.