The administration strategy amounts to a bet that there is safety in numbers. The best defense Obama can provide for his executive actions is to enlarge their constituencies before he leaves office. The more Americans who establish ties to Cuba through 2016, for instance, the more difficult it will be for even a Republican president in 2017 to disconnect the two nations. (Although Obama’s health care reform is grounded in legislation, not executive action, the principle is the same: The more people who are covered through the program, the tougher it will be to revoke that insurance later.)

Immigration could be where this dynamic unfolds most urgently. It may be impossible to win the 2016 GOP presidential nomination without promising to rescind Obama’s order of last November, which provided legal protection to as many as 5.2 million undocumented immigrants—nearly half of the estimated U.S. total. The president’s allies recognize that their best chance of protecting that order once Obama has left office is to pull so many people into the program that it will appear impractical to revoke their status, even if Republicans take the White House. As Los Angeles Mayor Eric Garcetti told me at a National Journal forum this week, “Any steps we can take forward [in legalizing undocumented immigrants] will show that it gets a little better, not worse. So [Americans will say], ‘What do we have to fear?’ ”
But it won’t be easy to persuade large numbers of undocumented immigrants, more accustomed to lowering their profile than raising it, to step forward to participate. Washington isn’t undertaking a big outreach program: Administration officials say that isn’t appropriate for an initiative that amounts to a decision not to prosecute people who are here illegally but who fit into certain protected categories (such as parents of U.S.-citizen children). That places a heavy burden on nonprofit groups and municipal governments to find the potentially eligible and lead them through the complex process.