A defiant President Obama on Thursday night will unveil his plan to shield 5 million undocumented immigrants from deportation, going around Congress on immigration reform and stoking a broader showdown with Republicans over the limits of his powers.

The presidential directive defers deportations for roughly 4.1 million immigrants in the country illegally whose children are American citizens or permanent residents. Under the executive action, the parents must have lived in the U.S. for at least five years to receive work permits.