From what I heard, it was a Rat bill attached to a budget provision that had the amnesty.
http://thomas.loc.gov/cgi-bin/bdquery/z?d099:SN01200:@@@S|TOM:/bss/d099query.html|
You may not like it, but it certainly wasn't "slipped through as a rider" or some such.
2. The debate over whether the 14th amendment should be interpreted as not making "anchor babies" US citizens, which has some possible merit, though contrary to all the historical practice, has NOTHING to do with Congress's power to pass amnesties, or alter the immigration laws in any way it chooses. That power is granted by the Naturalization Clause of the Constitution. So the 1986 law can't contradict any interpretation of the 14th Amendment. Similarly, a new interpretation of the 14th amendment today can't undo the citizenship of a person born here, to persons who were treated as citizens for 3 generations, because the ancestor was illegal in 1880!
3. I haven't dug into the Murder statistics controversy, but on another thread I dug up the fact that although something like 30% of FEDERAL prisoners are aliens, msot prisoners are state and local, and only about 7% of all prisoners are aliens. Since murder is almost always a state crime, it is plausible that maybe 7% of murders are committed by aliens, which would be 3-4 per day. However, you can probably find exact numbers in reports by either the FBI or the Bureau of Justice Statistics of the Department of Justice.