Fertility stats are culturally-telling

Via anncoulter.com, I read this great analysis of demographic statistics on fertility rates within the U.S. and in Europe. In sum, social conservatives (in my book, "conservatives") have more children (or simply have children) than do liberals. The author appears to be lamenting the statistic to some degree, for example, he draws this conclusion from the stats:

This dynamic helps explain the gradual drift of American culture toward religious fundamentalism and social conservatism. Among states that voted or President Bush in 2004, the average fertility rate is more than 11% higher than the rate of states for Sen. John Kerry.

However, he doesn't try to explain the differential in fertility rates. I'm not particularly troubled by dwindling populations raised within the Liberal worldview. But, unlike the Jihadiot baby boom happening in Europe, there is no reason (unless you're a Liberal Democrat) to be concerned about higher birth rates among God-fearing, golden-rule-valuing Americans.