Was it a Democrat, or Republican that said this?

I believe that this nation is the last hope of Western civilization and if this oasis of the world shall be overrun, perverted, contaminated or destroyed, then the last flickering light of humanity will be extinguished. I take no issue with those who would praise the contributions which have been made to our society by people of many races, of varied creeds and colors. America is indeed a joining together of many streams which go to form a mighty river which we call the American way. However, we have in the United States today hard-core, indigestible blocs which have not become integrated into the American way of life, but which, on the contrary are its deadly enemies. Today, as never before, untold millions are storming our gates for admission and those gates are cracking under the strain. The solution of the problems of Europe and Asia will not come through a transplanting of those problems en masse to the United States. ... I do not intend to become prophetic, but if the enemies of this legislation succeed in riddling it to pieces, or in amending it beyond recognition, they will have contributed more to promote this nation's downfall than any other group since we achieved our independence as a nation.[