The Sensenbrenner bill instantly turns millions of people into felons.
That is a flat out lie. The Congress cannot pass an ex post facto law which means that the illegals who crossed the border before its passage would be guilty of a misdemeanor not a felony. It is the illegal aliens who illegally cross the border after its enactment who will be felons.
Actually, if you are here "illegally", you are here "illegally". One might suppose that the application of the new law begins instantly, and you will not simply continue to exist in your prior state (here illegally but it's only a felony), but will restructure your corporeal being into a new state (here illegally, but it's a felony).
The only way you can purge yourself is to LEAVE FOR HOME.