Religion has always been a fault line in American politics. Throughout the colonial period, different regions of the United States were dominated by different religious groups, and in many ways these religious differences explain why the various regions of the United States developed unique political cultures. As was noted in Chapter 3 , over the course of the 19th century, new immigrants changed the religious landscape of America-thanks to widespread immigration from Catholic countries, the nation ceased to be overwhelmingly Protestant. The Catholic-Protestant divide played a major role in partisan politics in the United States until the latter years of the 20th century. The crucial religious divide in America is no longer between Catholics and Protestants, but between the religiously committed and the secular and the nominally religious. Americans exhibiting high levels of religious commitment tend to vote for the Republican Party, whereas those with no religious affi liation are more likely to support the Democratic Party. 1
As is the case throughout the developed world, the United States has experienced a serious decline in religiosity in recent decades-though this trend is less pronounced in the United States than in Western Europe. This is true of white Americans as well as other demographic groups in the United States. This trend presents a problem for the Republican Party. If the trend toward secularization continues, the portion of the electorate attracted to the party associated with traditional Christian values will shrink.