The way I see it, there are three reason against amnesty. Primarily, the corrupt Democrats use and depend on illegals voting ( and are against voters I.D.). Then there is the fact that we would be condoning an illegal act, thus neutering our immigration laws.
Finally, why flood a weak job situation with cheap labor? Face it, amnesty is just another cynical ploy by some very cunning thugs to effect governmental shift to the far left.