Unbridled undocumented immigration will serve to increase the hiring quotas for persons of Latino descent. The percentages will come out of everybody else's quota.
Suppose you have to move to a whiter community if you want to actually obtain one of the new jobs you are so sure the growth of our economy will produce, when it grows because of all the new workers. You won't need a bike carrier because you can just put your Flying Pigeon into your lifted pickup.
Sure, workers have to be qualified before anyone has to include them in a hiring quota but obtaining education won't take forever. It wouldn't take much to grant them amnesty and citizenship.
Whether or not any American Latinos think this way, they have a vested interest in opposing curbs to illegal immigration only so long as the people coming in are not good competition for them. They are probably in communication with each other before they come here.
The countries of origin have a vested interest in getting rid of their least employable people, so they're on board.
People often claim the ones with real enterprise and a love for our American values come here, but it cannot be denied that some of them at least might simply be fleeing poverty.