Executive actions on immigration have long history

President Obama’s executive action to protect millions of unauthorized immigrants from deportation is an act that both follows and departs from precedents set by his predecessors.

As immigrant advocates — and the White House itself — point out, presidents have a long history of using their discretionary enforcement powers to allow people to enter and remain in the country outside the regular immigration laws. But Obama’s move offers relief to more people than any other executive action in recent history — about 3.9 million people, or roughly 35% of the...