True, and if this nation's longest and most massive ever immigration influx were ever turned off, this might actually have some net effect on immigrant voting patterns. Until that happens, there's no way in hell "maturing" switchers from the Democratic party are going to keep pace with 1.5 million generally-poor people entering the citizenship queue every year, year after year. Sorry, it ain't gonna happen.
The problem with the esteemed President George Walker Bush's approach is that rather than save the prospects of the Party (and far more importantly the country), he instead makes multiple dead-of-night attempts to sneak pander-amnesties through Congress, cannibalizing the future to try to buy himself one last Congress and one more term.