A new report (pdf) from the Immigration Policy Center reminds us that immigrant arrivals are actually down since well before our current wave of nativist sentiment:
The annual flow of new immigrants to the United States appears to have peaked around 2000, and projections by the census Bureau and Social Security Administration foresee continued decline through 2015 or longer. In contrast, proponents of the negative story of the immigrant future have ignored this recent leveling and decline. Instead, they have averaged data from the last 12 to 14 years and concluded that immigration is continuing at record levels.
As Demographer Dowell Myers explains, the flow to gateway states like California is way down–so much so that total arrivals are in decline. Immigrants are instead heading straight to places like Missouri and South Carolina, where they're finding jobs, forming small communities, and generally terrifying Buddy Witherspoon supporters.