The Arizonan trend showing a steeper decline in the Hispanic fertility rate than in the non-Hispanic black and white fertility rates over the last several years is not an anomaly, but instead illustrative of the same sort of fertility pattern at the national level. Over the three year period from 2007-2009, Hispanic fertility declined at three times the rate of the non-Hispanic white fertility decline. The rates for non-Hispanic blacks, Asians, and Native Americans declined at at a slightly faster clip than for non-Hispanic whites:
This is not to confuse the pace of declines with absolute fertility rates. Hispanics, even in 2009, were still considerably more fecund than non-Hispanics. The following table shows the total fertility rate of women by race in 2007 and also in 2009:
If trends continue at the same pace for each classification (which strikes me as highly unlikely), there will be near birthrate parity, at 50 births per 1000 women, for all five racial groups in 2031--a situation in which the TFR for all groups would be well below what is needed for population replacement to occur.
Thanks to Mark Wethman, who keeps a keen eye on these things, for the heads-up.