In an executive order to be issued as early as next week, President Obama will order changes in the enforcement of the government’s immigration rules. One part of the plan will allow parents of children who are American citizens or legal residents to obtain legal work documents and no longer fear being separated from their families, a move that could affect as many as 3.3 million people. It will also extend protections to those who came as undocumented children, which could affect an additional 1 million. The president will also reportedly address immigration for those with high-tech skills, increase border resources, and make clearer laws about those who are low priority for deportation. It will also include a memorandum that will make clear that deportations should continue for convicted criminals, recent border crossers, and foreigners who pose national-security risks. Republicans plan to fight it at every step, from budget negotiations to confirmation hearings for nominees.