I think they have to, but their feet are being held to the fire by business groups, which are grimly determined to break U.S. wages permanently and bottomlessly. Business guys think they can get on top of wages for as far as the eye can see, and I think they are demanding the GOP go for it on both wages (immigration) and taxes -- they evidently must think that if they can just get over, the Democrats will never be able to undo the damage business can do to "move-up" wages by sapping the lower end of the wage scale with an uncontrolled flood of illegals.
The Japanese military used to call this "breaking the jewel" -- destructive use of a military formation or unit. That is what the business clerisy appears to be doing with the GOP.
Maybe they think that if they destroy the GOP in the process, it'll be no big deal, because then they'll be rich enough to go out and buy a new political party.
Then let the sumbiches sell their crap to the third world. Thats what really p*sses me off... they want to use third world labor & charge first world prices.
They must know its not sustainable, that they are killing the Goose That Laid the Golden Egg, but-they-just-don't-care.