The ruling by a federal district judge that the executive branch may indefinitely detain immigrants who have been held deportable by an immigration judge, even on discriminatory grounds, doesn't strike me as the total repudiation of the Constitution that some on the left believe it, but it also doesn't seem as obviously wise as the right thinks, either. If someone is deportable, then I think it is up to the INS/DHS's discretion whether to deport the person, and if they choose to exercise that discretion based on the person's religion or national origin, tough toenails. What I find objectionable is the aspect of the ruling that allows the government to hold people for as long as an official thinks good, with apparently no bounds.
When an immigration judge issues an order of deportation, either the U.S. wants the immigrant gone immediately and shoves him onto a flight, or gives her a bit more grace and lets her leave on her own steam and at her own expense within a few months. Some people don't comply with the order and aren't annoying enough to hunt down, so they stay in the country by grace of bureaucratic overload. But I don't understand what gives the U.S. the right to take a deportable person and deprive him of his liberty without charging him with a crime, prosecuting him and giving him the opportunity to be convicted and properly imprisoned or freed. I agree with the conservatives that if you violate the terms of your stay even by failing to do the paperwork properly, you shouldn't get too pissy when you get kicked out. I am dumbfounded by the conservatives' belief that overstaying a visa makes you the equivalent of a felon convicted of a life-sentence crime.
My infant understanding of immigration law is that violatons of it -- as opposed to violations of other laws that apply to citizens as well as non-citizens -- are penalized by loss of one's status as an immigrant. Punishing people who have violated only the immigration law, particularly when they have done so without mens rea (i.e. forgotten to renew their visa, in contrast to those who are consciously dodging the Border Patrol), with indefinite imprisonment is stretching the government's immigration powers too far and for a purpose with no connection to the proper means and ends of immigration law.