Religious "leaders" such as Land are often notably shallow people whose thinking goes no deeper than sophomoric sentiment. In this case, the "leaders" overlook the basic principle that the U.S. exists for the benefit of its own citizens, just as it says in the Constitution's preamble. The massive presence of illegal aliens -- or of amnestied illegal aliens -- is a great detriment, not a benefit, to the American public at large.
Polls show an enormous gap between the views of "leaders" on this subject and the views of the rank-and-file. See http://www.cis.org/articles/2006/back406.pdf