From The Economist:
Together with a general migration from the north-east and Midwest towards the sunbelt, the number of people leaving the faith has led to a shrinking of Catholicism in its former heartlands….
This shrinking has been offset by growth in the South and southwest of the country. The number of Catholics in the archdiocese of Atlanta has increased by 180% in 2001-11. In these growth areas two-thirds of all Catholics are Hispanic. Hispanics tend to have larger families and their children are more likely to stick with the religion than the offspring of white Catholics. This is causing a big change in the ethnic makeup of the faithful. About a third of American Catholics are Hispanic, but for those under 40 the share rises to almost half. The church’s building programme cannot keep up. In some parishes in Arizona the local church will hold up to seven services on a Sunday, says Gerald Kicanus, the bishop of Tucson. Finding enough pastors is hard: the diocese has brought in priests from Nigeria, India and the Philippines to make up for a shortage of home-grown ones.
Once they have found a pew, Hispanic Catholics expect a different kind of worship. Cross-carrying processions during Holy Week have become commonplace. The way the sign of the cross is made can differ, as can the use of holy water and the saints and shrines chosen for veneration—the growing cult of the Virgin of Guadalupe is the best example. Services have more music, and the kind of charismatic preaching performed by Father Hoyos in Arlington has gained ground.
This distinctive way of doing things extends to politics. Overall, America’s Catholics vote like the country as a whole. In 2012, 50% of Catholic voters backed Barack Obama and 48% went for Mitt Romney, his Republican opponent. But there was a clear divide between white Catholics, who favoured Mr Romney, and Hispanic Catholics, who favoured Mr Obama.
Though Hispanic Catholics are conservative on some social issues, such as abortion, this seldom determines their party allegiance. (The same is true of black evangelicals.) Their notion of the proper role of government is more Democratic than Republican. Some 61% of white Catholics say it should reduce the income gap between rich and poor. For Hispanic Catholics the figure is 86%. For Mr Obama, who was to meet the pope on March 27th, these numbers must seem miraculous.
So Latino immigration helps fill Roman Catholic churches and brings votes the Democrats’ way.
And both that church and that party favor more of it.
Possibly a phenonemenon that it does not need a Sherlock Holmes to explain.