What he can't do
1. The president can't bar people from applying for political asylum. Those guidelines are set by the United Nations Refugee Convention, which the United States has signed, said Stephen Yale-Loehr, an immigration attorney and professor at Cornell University Law School.
2. And no, the President can't increase the number eligible for green cards because their spouses or parents are U.S. citizens. Such matters are set by law. Though some immigration advocates have argued spouses and children shouldn't count toward 140,000 limit on employment-based green cards, whether the President can make that kind of change unilaterally is murky territory.
3. Obama also can't just eliminate judicial review for people ordered deported — such a move would violate the Constitution.
4. Nor can he just load up all undocumented immigrants on a bus and deport them without some sort of legal hearing. That type of action also would violate the law.
"The Constitution says that all persons have due process rights in the U.S. whether they are from another country or the U.S.," Yale-Loehr said.
5. And, for those hoping for (or fearing) a blanket executive action legalizing all undocumented immigrants, no the President can't do that either. There's a law for that.
"There are constitutional limits on what the president can do. We have a tripartite government system. The Congress enacts the laws; the President enact the laws," Yale-Loehr said. "The President cannot create an immigration policy willy-nilly, whole cloth. He cannot create an immigration law. He has to get Congress' approval to change an immigration law. "